diff --git a/.gitignore b/.gitignore
index e0eb3bf..50d4412 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,7 +5,7 @@ target/
 !**/src/test/**/out/
 *.iml
 .idea/
-
+*.class
 
 ### Mac OS ###
 .DS_Store
diff --git a/src/main/java/com/javarush/karpeev/command/CryptText.java b/src/main/java/com/javarush/karpeev/command/CryptText.java
new file mode 100644
index 0000000..5a82ed7
--- /dev/null
+++ b/src/main/java/com/javarush/karpeev/command/CryptText.java
@@ -0,0 +1,84 @@
+package com.javarush.karpeev.command;
+
+import com.javarush.karpeev.constants.Constants;
+
+import java.util.Arrays;
+
+public class CryptText {
+    public char[] encrypt(char[] arrayInputText, int key) {
+        char[] arrayOutputText = new char[arrayInputText.length];
+        for (int i = 0; i < arrayInputText.length; i++) {
+            if (arrayInputText[i] == '\n') {
+                arrayOutputText[i] = arrayInputText[i];
+                continue;
+            }
+            for (int j = 0; j < Constants.alphabet.length; j++) {
+                if (arrayInputText[i] == Constants.alphabet[j]) {
+                    if (j + key > Constants.alphabet.length - 1) {
+                        arrayOutputText[i] = Constants.alphabet[(j + key) % Constants.alphabet.length];
+                    } else {
+                        arrayOutputText[i] = Constants.alphabet[j + key];
+                    }
+                }
+            }
+        }
+        return arrayOutputText;
+    }
+
+    public char[] decrypt(char[] arrayInputText, int key) {
+        char[] arrayOutputText = new char[arrayInputText.length];
+        for (int i = 0; i < arrayInputText.length; i++) {
+            if (arrayInputText[i] == '\n') {
+                arrayOutputText[i] = arrayInputText[i];
+                continue;
+            }
+            for (int j = 0; j < Constants.alphabet.length; j++) {
+                if (arrayInputText[i] == Constants.alphabet[j]) {
+                    if (j - key < 0) {
+                        arrayOutputText[i] = Constants.alphabet[Constants.alphabet.length + j - key];
+                    } else {
+                        arrayOutputText[i] = Constants.alphabet[j - key];
+                    }
+                }
+            }
+        }
+        return arrayOutputText;
+    }
+
+    public int bruteForce(char[] arrayDecodeText) {
+        int correctKey = 0;
+        int maxAmount = 0;
+        char[] bufferArrayChar;
+        arrayDecodeText = Arrays.copyOf(arrayDecodeText, Math.min(arrayDecodeText.length, Constants.LIMIT_SYMBOLS_FOR_FOUND_KEY));
+        for (int key = 0; key < Constants.alphabet.length; key++) {
+            int amountConjunction = 0;
+            bufferArrayChar = decrypt(arrayDecodeText, key);
+            for (int i = 0; i < bufferArrayChar.length; i++) {
+                amountConjunction += isCorrectKey(bufferArrayChar, i);
+            }
+            if (amountConjunction > maxAmount) {
+                maxAmount = amountConjunction;
+                correctKey = key;
+            }
+        }
+        return correctKey;
+    }
+
+    public int isCorrectKey(char[] arrayChar, int i) {
+        int amountConjunction = 0;
+        if (arrayChar[i] == ' ') {
+            amountConjunction++;
+        }
+        if (i + 2 < arrayChar.length && arrayChar[i] == ',' && arrayChar[i + 1] == ' ' && Character.isLetter(arrayChar[i + 2])) {
+            amountConjunction += Constants.COEFFICIENT_EFFICIENCY;
+        }
+        if (i + 2 < arrayChar.length && arrayChar[i] == ' ' && Character.isLetter(arrayChar[i + 1]) && arrayChar[i + 2] == ' ') {
+            amountConjunction++;
+        }
+        if (i + 2 < arrayChar.length && arrayChar[i] == '.' && arrayChar[i + 1] == ' ' &&
+                Character.isLetter(arrayChar[i + 2]) && Character.isUpperCase(arrayChar[i + 2])) {
+            amountConjunction += Constants.COEFFICIENT_EFFICIENCY;
+        }
+        return amountConjunction;
+    }
+}
diff --git a/src/main/java/com/javarush/karpeev/console/Menu.java b/src/main/java/com/javarush/karpeev/console/Menu.java
new file mode 100644
index 0000000..9c1695b
--- /dev/null
+++ b/src/main/java/com/javarush/karpeev/console/Menu.java
@@ -0,0 +1,109 @@
+package com.javarush.karpeev.console;
+
+import com.javarush.karpeev.exceptions.FileForReadNotFoundException;
+import com.javarush.karpeev.exceptions.FileForWriteNotFoundException;
+import com.javarush.karpeev.fileManager.FileManager;
+import com.javarush.karpeev.command.CryptText;
+import com.javarush.karpeev.constants.Constants;
+import com.javarush.karpeev.constants.Message;
+
+import java.util.Scanner;
+
+public class Menu {
+    private int key;
+    private int step = Constants.STEP_START;
+
+    Scanner input = new Scanner(System.in);
+
+    public void getMenu() {
+        System.out.println(Message.WELCOME);
+        while (step != Constants.STEP_EXIT) {
+            switch (getStep()) {
+                case 1 -> coding();
+                case 2 -> decoding();
+                case 3 -> foundKey();
+                default -> System.out.println(Message.BAY);
+            }
+        }
+    }
+
+    private void coding() {
+        FileManager fileManager = new FileManager();
+        CryptText cryptText = new CryptText();
+        getKey();
+        try {
+            char[] arrayEncrypt = cryptText.encrypt(fileManager.varyTextInArrayChar(fileManager.getPathReadeFile()), key);
+            fileManager.writeTextInFile(fileManager.getPathWriteFile(), arrayEncrypt, arrayEncrypt.length);
+            System.out.println(Message.END_CODE + Message.NEXT_STEP);
+        } catch (FileForReadNotFoundException e) {
+            System.out.println(Message.NOT_FOUND_FILE_FOR_READ + Message.NEXT_STEP);
+        } catch (FileForWriteNotFoundException e) {
+            System.out.println(Message.NOT_FOUND_FILE_FOR_WRITE + Message.NEXT_STEP);
+        }
+    }
+
+    private void decoding() {
+        FileManager fileManager = new FileManager();
+        CryptText cryptText = new CryptText();
+        getKey();
+        try {
+            char[] arrayForDecrypt = cryptText.decrypt(fileManager.varyTextInArrayChar(fileManager.getPathReadeFile()), key);
+            fileManager.writeTextInFile(fileManager.getPathWriteFile(), arrayForDecrypt, arrayForDecrypt.length);
+            System.out.println(Message.END_DECODE + Message.NEXT_STEP);
+        } catch (FileForReadNotFoundException e) {
+            System.out.println(Message.NOT_FOUND_FILE_FOR_READ + Message.NEXT_STEP);
+        } catch (FileForWriteNotFoundException e) {
+            System.out.println(Message.NOT_FOUND_FILE_FOR_WRITE + Message.NEXT_STEP);
+        }
+    }
+
+    private void foundKey() {
+        FileManager fileManager = new FileManager();
+        CryptText cryptText = new CryptText();
+        try {
+            char[] arrayDecrypt = fileManager.varyTextInArrayChar(fileManager.getPathFoundKey());
+            key = cryptText.bruteForce(arrayDecrypt);
+            fileManager.writeTextInFile(fileManager.getPathWriteFile(), cryptText.decrypt(arrayDecrypt, key), arrayDecrypt.length);
+            System.out.println(Message.END_DECODE + Message.END_FOUND_KEY + key + Message.NEXT_STEP);
+        } catch (FileForReadNotFoundException e) {
+            System.out.println(Message.NOT_FOUND_FILE_FOR_READ + Message.NEXT_STEP);
+        } catch (FileForWriteNotFoundException e) {
+            System.out.println(Message.NOT_FOUND_FILE_FOR_WRITE + Message.NEXT_STEP);
+        }
+    }
+
+    private int getStep() {
+        while (true) {
+            System.out.println(Message.MENU);
+            try {
+                step = Integer.parseInt(input.nextLine());
+            } catch (NumberFormatException e) {
+                System.out.println(Message.NOT_NUMBER);
+                continue;
+            }
+            if (step < Constants.INTERVAL_STEP_MENU_START || step > Constants.INTERVAL_STEP_MENU_END) {
+                System.out.println(Message.NUMBER_NOT_IN_MENU);
+            } else {
+                break;
+            }
+        }
+        return step;
+    }
+
+    public void getKey() {
+        while (true) {
+            System.out.print(Message.INPUT_KEY + (Constants.alphabet.length - 1) + ": ");
+            try {
+                key = Integer.parseInt(input.nextLine());
+            } catch (NumberFormatException e) {
+                System.out.println(Message.NOT_NUMBER_KEY + (Constants.alphabet.length - 1) + ": ");
+                continue;
+            }
+            if (key < 1 || key > Constants.alphabet.length - 1) {
+                System.out.println(Message.FALSE_NUMBER + (Constants.alphabet.length - 1) + ": ");
+            } else {
+                break;
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/com/javarush/karpeev/constants/Constants.java b/src/main/java/com/javarush/karpeev/constants/Constants.java
new file mode 100644
index 0000000..e43efd0
--- /dev/null
+++ b/src/main/java/com/javarush/karpeev/constants/Constants.java
@@ -0,0 +1,26 @@
+package com.javarush.karpeev.constants;
+public class Constants {
+    public static final char[] alphabet = {
+            'а', 'б', 'в', 'г', 'д', 'е', 'ё', 'ж', 'з', 'и', 'й',
+            'к', 'л', 'м', 'н', 'о', 'п', 'р', 'с', 'т', 'у', 'ф',
+            'х', 'ц', 'ч', 'ш', 'щ', 'ъ', 'ы', 'ь', 'э', 'ю', 'я',
+            '1', '2', '3', '4', '5', '6', '7', '8', '9', '0',
+            'А', 'Б', 'В', 'Г', 'Д', 'Е', 'Ё', 'Ж', 'З', 'И', 'Й',
+            'К', 'Л', 'М', 'Н', 'О', 'П', 'Р', 'С', 'Т', 'У', 'Ф',
+            'Х', 'Ц', 'Ч', 'Ш', 'Щ', 'Ъ', 'Ы', 'Ь', 'Э', 'Ю', 'Я',
+            '~', '!', '@', '#', '$', '№', ':', '^', '&', '?', '*', '(', ')', '{', '}', '-', '«', '»',
+            '_', ',', '/', '.', '…', '|', '<', '>', '+', ';', '%', '"', '`', '=', '\'', '\\', ' ', '—',
+            'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
+            'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
+            'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
+            'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'
+    };
+
+    public static final int COEFFICIENT_EFFICIENCY = 10;
+    public static final int LIMIT_SYMBOLS_FOR_FOUND_KEY = 1000;
+    public static final int STEP_START = -1;
+    public static final int INTERVAL_STEP_MENU_START = 0;
+    public static final int INTERVAL_STEP_MENU_END = 3;
+    public static final int STEP_EXIT = 0;
+
+}
\ No newline at end of file
diff --git a/src/main/java/com/javarush/karpeev/constants/Message.java b/src/main/java/com/javarush/karpeev/constants/Message.java
new file mode 100644
index 0000000..66c58a8
--- /dev/null
+++ b/src/main/java/com/javarush/karpeev/constants/Message.java
@@ -0,0 +1,22 @@
+package com.javarush.karpeev.constants;
+
+public class Message {
+    public static final String NOT_NUMBER = "Вы ввели текст или нецелое число. Введите число от 0 до 3";
+    public static final String NOT_NUMBER_KEY = "Вы ввели текст или нецелое число. Введите целое число от 1 до ";
+    public static final String INPUT_PATH_READ_FILE = "Введите адрес файла с текстом для шифрования: ";
+    public static final String INPUT_PATH_FOR_FOUND_KEY = "Введите адрес зашифрованного текстового файла для поиска ключа: ";
+    public static final String INPUT_PATH_WRITE_FILE = "Введите адрес файла для записи: ";
+    public static final String FALSE_NUMBER = "Вы ввели число, которое не входит в диапазон от 1 до ";
+    public static final String NUMBER_NOT_IN_MENU = "\nЧисло не соответствует входному условию. Введите число от 0 до 3";
+    public static final String MENU = "1 - Шифрование\n2 - Расшифровка\n3 - Поиск ключа расшифровки\n0 - Выход";
+    public static final String WELCOME = "\nДобро пожаловать в шифратор!\n\nВведите действие в соответствии с пунктом в меню:";
+    public static final String INPUT_KEY = "Введите ключ - положительное целое число от 1 до ";
+    public static final String NEXT_STEP = "\nДля дальнейших действий выберите пункт в меню.\n";
+    public static final String END_CODE = "Шифрование выполнено!";
+    public static final String END_DECODE = "Расшифровка выполнена! ";
+    public static final String END_FOUND_KEY = "Поиск ключа выполнен! \nКорректный ключ: ";
+    public static final String NOT_FOUND_FILE_FOR_READ = "\nФайл для чтения текста не найден! Попробуйте ещё раз\n";
+    public static final String NOT_FOUND_FILE_FOR_WRITE = "\nФайл для записи не найден! Попробуйте ещё раз\n";
+    public static final String BAY = "До скорой встречи!";
+}
+
diff --git a/src/main/java/com/javarush/karpeev/exceptions/FileForReadNotFoundException.java b/src/main/java/com/javarush/karpeev/exceptions/FileForReadNotFoundException.java
new file mode 100644
index 0000000..54c9175
--- /dev/null
+++ b/src/main/java/com/javarush/karpeev/exceptions/FileForReadNotFoundException.java
@@ -0,0 +1,8 @@
+package com.javarush.karpeev.exceptions;
+
+import java.io.IOException;
+
+public class FileForReadNotFoundException extends IOException {
+    public FileForReadNotFoundException() {
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/com/javarush/karpeev/exceptions/FileForWriteNotFoundException.java b/src/main/java/com/javarush/karpeev/exceptions/FileForWriteNotFoundException.java
new file mode 100644
index 0000000..914a105
--- /dev/null
+++ b/src/main/java/com/javarush/karpeev/exceptions/FileForWriteNotFoundException.java
@@ -0,0 +1,8 @@
+package com.javarush.karpeev.exceptions;
+
+import java.io.IOException;
+
+public class FileForWriteNotFoundException extends IOException {
+    public FileForWriteNotFoundException() {
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/com/javarush/karpeev/fileManager/FileManager.java b/src/main/java/com/javarush/karpeev/fileManager/FileManager.java
new file mode 100644
index 0000000..851fae7
--- /dev/null
+++ b/src/main/java/com/javarush/karpeev/fileManager/FileManager.java
@@ -0,0 +1,54 @@
+package com.javarush.karpeev.fileManager;
+
+import com.javarush.karpeev.exceptions.FileForReadNotFoundException;
+import com.javarush.karpeev.exceptions.FileForWriteNotFoundException;
+import com.javarush.karpeev.constants.Message;
+
+import java.io.*;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Scanner;
+
+public class FileManager {
+    Scanner scanner = new Scanner(System.in);
+
+    public char[] varyTextInArrayChar(String addressText) throws FileForReadNotFoundException {
+        StringBuilder textBuffer = new StringBuilder();
+        try (BufferedReader reader = new BufferedReader(new FileReader(addressText))) {
+            while (reader.ready()) {
+                textBuffer.append(reader.readLine()).append('\n');
+            }
+        } catch (IOException e) {
+            throw new FileForReadNotFoundException();
+        }
+        textBuffer.deleteCharAt(textBuffer.length() - 1);
+        return textBuffer.toString().toCharArray();
+    }
+
+    public void writeTextInFile(String addressFileForWrite, char[] mas, int len) throws FileForWriteNotFoundException {
+        File file = new File(addressFileForWrite);
+        if (!file.exists()) {
+            throw new FileForWriteNotFoundException();
+        }
+        try (BufferedWriter writer = Files.newBufferedWriter(Path.of(addressFileForWrite))) {
+            writer.write(mas, 0, len);
+        } catch (IOException e) {
+            throw new FileForWriteNotFoundException();
+        }
+    }
+
+    public String getPathReadeFile() {
+        System.out.print(Message.INPUT_PATH_READ_FILE);
+        return scanner.nextLine();
+    }
+
+    public String getPathFoundKey() {
+        System.out.print(Message.INPUT_PATH_FOR_FOUND_KEY);
+        return scanner.nextLine();
+    }
+
+    public String getPathWriteFile() throws FileForWriteNotFoundException {
+        System.out.print(Message.INPUT_PATH_WRITE_FILE);
+        return scanner.nextLine();
+    }
+}
diff --git a/src/main/java/com/javarush/karpeev/main/Runner.java b/src/main/java/com/javarush/karpeev/main/Runner.java
new file mode 100644
index 0000000..93a9ab2
--- /dev/null
+++ b/src/main/java/com/javarush/karpeev/main/Runner.java
@@ -0,0 +1,10 @@
+package com.javarush.karpeev.main;
+
+import com.javarush.karpeev.console.Menu;
+
+public class Runner {
+    public static void main(String[] args) {
+        Menu menu = new Menu();
+        menu.getMenu();
+    }
+}