diff --git a/README.md b/README.md
index e93444f..798a6fa 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,4 @@
+Стариков Егор, группа 142
 # Контрольная работа 1 (2 вариант)
 
 Темы: Git и GitHub, стандарты оформления кода, хорошие практики, тестирование.
diff --git a/src/bin_search.py b/src/bin_search.py
index 713abfc..5c60ba9 100644
--- a/src/bin_search.py
+++ b/src/bin_search.py
@@ -1,10 +1,13 @@
-def binSearch(xs: list[int], x: int):
+def bin_search(xs: list[int], x: int):
     left, right = 0, len(xs) - 1
-    while left < right:
+    for i in range(len(xs) - 1):
+        if xs[i] > xs[i + 1]:
+            return -1
+    while left <= right:
         mid = (left + right) // 2
         if xs[mid] == x:
             return mid
-        if xs[mid] < x:
+        elif xs[mid] < x:
             left = mid + 1
         else:
             right = mid - 1
diff --git a/src/checksum.py b/src/checksum.py
index 74b4fb0..6628803 100644
--- a/src/checksum.py
+++ b/src/checksum.py
@@ -1,14 +1,38 @@
-def modulo11Checksum(ISBNNumber: str):
+def modulo11checksum(isbn_number: str):
 
-    digits = [int(char) for char in ISBNNumber if char.isdigit()]
+    digits = [int(char) for char in isbn_number if char.isdigit()]
 
-    checkDigit = digits[-1]
+    if len(digits) < 9:
+        return False
+
+    last_char = isbn_number[-1]
+    if last_char.upper() == 'X':
+        check_digit = 10
+    elif last_char.isdigit():
+        check_digit = digits[-1]
+    else:
+        return False
 
     total = 0
-    for i in range(len(digits) - 1):
-        weight = 10
+    for i in range(9):
+        weight = 10 - i
         digit = digits[i]
         total += digit * weight
 
-    checksum = total + checkDigit
+    checksum = total + check_digit
     return checksum % 11 == 0
+
+print("Введите номер:")
+s = input()
+while True:
+    if modulo11checksum(s):
+        print("Все верно")
+    elif s == "-1":
+        break
+    else:
+        print("Что-то не так")
+    print("Введите номер:")
+    s = input()
+
+
+
diff --git a/test/test_bin_searh.py b/test/test_bin_searh.py
index d18d85b..52b55d5 100644
--- a/test/test_bin_searh.py
+++ b/test/test_bin_searh.py
@@ -1,13 +1,16 @@
-from src.bin_search import binSearch
+from src.bin_search import bin_search
 
 
 def test_middle():
-    assert binSearch([1, 2, 3, 4, 5], 4) == 3
+    assert bin_search([1, 2, 3, 4, 5], 3) == 2
+
+def not_sorted_list():
+    assert bin_search([2, 4, 1, 3], 1) == -1
 
 
 def test_start():
-    assert binSearch([1, 2, 3, 4], 2) == 1
+    assert bin_search([1, 2, 3, 4], 2) == 1
 
 
 def test_not_in_list():
-    assert binSearch([1, 2, 3, 4], 5) == -1
+    assert bin_search([1, 2, 3, 4], 5) == -1
diff --git a/test/test_checksum.py b/test/test_checksum.py
index f64a64c..a25285a 100644
--- a/test/test_checksum.py
+++ b/test/test_checksum.py
@@ -1,9 +1,20 @@
-from src.checksum import modulo11Checksum
+from src.checksum import modulo11checksum
 
 
 def test_good():
-    assert modulo11Checksum("2-266-11156-8")
+    assert modulo11checksum("2-266-11156-6")
 
 
 def test_bad():
-    assert not modulo11Checksum("2-266-11156-3")
+    assert not modulo11checksum("2-266-11156-3")
+
+def test_x():
+    assert modulo11checksum("0-8044-2957-X")
+
+def test_no_correct():
+    assert not modulo11checksum("123456789Y")
+
+def test_len():
+    assert not modulo11checksum("31231")
+
+