diff --git a/homework3/CMakeLists.txt b/homework3/CMakeLists.txt
new file mode 100644
index 0000000..273f811
--- /dev/null
+++ b/homework3/CMakeLists.txt
@@ -0,0 +1,12 @@
+cmake_minimum_required(VERSION 3.10)
+project(CProgrammingTasks homework3)
+
+# Включаем предупреждения
+if(CMAKE_C_COMPILER_ID MATCHES "GNU|Clang")
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -Wpedantic")
+endif()
+
+# Создаем исполняемые файлы для каждой задачи
+add_executable(task1 src/task1Balance.c)
+add_executable(task2 src/task2Strings.c)
+add_executable(task3 src/task3ZeroCount.c )
diff --git a/homework3/src/task1Balance.c b/homework3/src/task1Balance.c
new file mode 100644
index 0000000..ef6fbab
--- /dev/null
+++ b/homework3/src/task1Balance.c
@@ -0,0 +1,33 @@
+#include <stdio.h>
+#include <string.h>
+
+int main()
+{
+    int balance = 0;
+    char origString[100];
+    printf("введите строку: ");
+    scanf("%99s", origString);
+
+    int l = strlen(origString);
+    for (int i = 0; i < l; i++) {
+        char s = origString[i];
+
+        if (s == '(')
+            balance++;
+        if (s == ')')
+            balance--;
+
+        if (balance < 0) {
+            printf("не выполняется правило вложенности скобок\n");
+            return 0;
+        }
+    }
+
+    if (balance != 0) {
+        printf("не выполняется правило вложенности скобок\n");
+        return 0;
+    }
+
+    printf("баланс скобок соблюдается\n");
+    return 0;
+}
diff --git a/homework3/src/task2Strings.c b/homework3/src/task2Strings.c
new file mode 100644
index 0000000..8baa28f
--- /dev/null
+++ b/homework3/src/task2Strings.c
@@ -0,0 +1,41 @@
+#include <stdio.h>
+#include <string.h>
+
+int main()
+{
+    char s[100];
+    char s1[100];
+
+    printf("input string s: ");
+    scanf("%99s", s);
+
+    printf("input substring s1: ");
+    scanf("%99s", s1);
+
+    int count = 0;
+    int sLength = strlen(s);
+    int s1Length = strlen(s1);
+
+    if (s1Length == 0 || s1Length > sLength) {
+        printf("number of occurrences: %d\n", count);
+        return 0;
+    }
+
+    for (int i = 0; i <= sLength - s1Length; i++) {
+        int found = 1;
+
+        for (int j = 0; j < s1Length; j++) {
+            if (s[i + j] != s1[j]) {
+                found = 0;
+                break;
+            }
+        }
+
+        if (found) {
+            count++;
+        }
+    }
+
+    printf("number of occurrences '%s' in '%s': %d\n", s1, s, count);
+    return 0;
+}
diff --git a/homework3/src/task3ZeroCount.c b/homework3/src/task3ZeroCount.c
new file mode 100644
index 0000000..1efbbfb
--- /dev/null
+++ b/homework3/src/task3ZeroCount.c
@@ -0,0 +1,31 @@
+#include <stdio.h>
+
+#define MAXSIZE 100
+
+int main()
+{
+    int arr[MAXSIZE];
+    int n;
+    printf("input the size of the array (no more than %d): ", MAXSIZE);
+    scanf("%d", &n);
+
+    if (n <= 0 || n > MAXSIZE) {
+        printf("incorrect array size!");
+        return 1;
+    }
+
+    printf("input %d elemens\n", n);
+
+    for (int i = 0; i < n; i++) {
+        printf("element %d: ", i + 1);
+        scanf("%d", &arr[i]);
+    }
+
+    int zeroCount = 0;
+    for (int i = 0; i < n; i++) {
+        if (arr[i] == 0)
+            zeroCount++;
+    }
+    printf("the number of zero elements in the array is %d\n", zeroCount);
+    return 0;
+}