diff --git a/aux_lib.c b/aux_lib.c
index 469bd42..a783689 100644
--- a/aux_lib.c
+++ b/aux_lib.c
@@ -1,22 +1,38 @@
 #include "aux_lib.h"
+#include <stdbool.h>
 
-/*
- * Функция возвращает n-ный элемент последовательности фибоначи
- */
 int
 fibonacci(int nitem)
 {
-	//YOUR_CODE
-	return 42;
+        if (nitem <= 1) {
+            return nitem;
+        }
+        int a = 0, b = 1, next;
+        for (int i = 2; i <= nitem; ++i) {
+            next = a + b;
+            a = b;
+            b = next;
+        }
+        return b;
 }
 
-/*
- * Функция считает сумму элементов массива и возвращает информацию
- * является ли эта сумма нечётным числом.
- */
 bool
 sum_is_odd(int *arr, int arrsz)
 {
-	//YOUR_CODE
-	return false;
+        long long sum = 0; 
+        for (int i = 0; i < arrsz; i++) {
+            sum += arr[i];
+        }
+        return sum % 2 != 0;
+}
+
+int bit_count(unsigned int number) {
+    int count = 0;
+    while (number > 0) {
+        if (number % 2 == 1) {
+            count++;
+        }
+        number = number / 2; 
+    }
+    return count;
 }
diff --git a/aux_lib.h b/aux_lib.h
index bcf878c..fca2485 100644
--- a/aux_lib.h
+++ b/aux_lib.h
@@ -5,3 +5,4 @@ int fibonacci(int nitem);
 
 bool sum_is_odd(int *arr, int arrsz);
 
+int bit_count(unsigned int number);
diff --git a/aux_test.c b/aux_test.c
index 0de7fbf..546585b 100644
--- a/aux_test.c
+++ b/aux_test.c
@@ -1,15 +1,67 @@
 #include <stdio.h>
-#include "munit.h"
+#include "munit/munit.h"
 #include "aux_lib.h"
+#include <stdbool.h> 
+
+static MunitResult test_fibonacci_base(const MunitParameter params[], void* fixture) {
+    munit_assert_int(fibonacci(0), ==, 0);
+    munit_assert_int(fibonacci(1), ==, 1);
+    munit_assert_int(fibonacci(2), ==, 1);
+    munit_assert_int(fibonacci(3), ==, 2);
+    return MUNIT_OK;
+}
+
+
+
+static MunitResult test_bit_count(const MunitParameter params[], void* fixture) {
+    munit_assert_int(bit_count(0), ==, 0);
+    munit_assert_int(bit_count(1), ==, 1);
+    munit_assert_int(bit_count(3), ==, 2);
+    munit_assert_int(bit_count(8), ==, 1);
+    munit_assert_int(bit_count(255), ==, 8);
+    munit_assert_int(bit_count(0xFFFFFFFF), ==, 32); 
+    return MUNIT_OK;
+}
+
+static MunitResult test_fibonacci_advanced(const MunitParameter params[], void* fixture) {
+    munit_assert_int(fibonacci(10), ==, 55);
+    munit_assert_int(fibonacci(20), ==, 6765);
+    return MUNIT_OK;
+}
+
+static MunitResult test_sum_odd(const MunitParameter params[], void* fixture) {
+    int arr[] = {1, 2, 3, 4, 5}; 
+    munit_assert_true(sum_is_odd(arr, 5));
+    return MUNIT_OK;
+}
+
+static MunitResult test_sum_even(const MunitParameter params[], void* fixture) {
+    int arr[] = {1, 2, 3, 4, 5, 1};
+    munit_assert_false(sum_is_odd(arr, 6));
+    return MUNIT_OK;
+}
+
+static MunitTest test_suite_tests[] = {
+    { (char*) "fibonacci base cases", test_fibonacci_base, NULL, NULL, MUNIT_TEST_OPTION_NONE, NULL },
+    { (char*) "fibonacci advanced cases", test_fibonacci_advanced, NULL, NULL, MUNIT_TEST_OPTION_NONE, NULL },
+    { (char*) "sum odd array", test_sum_odd, NULL, NULL, MUNIT_TEST_OPTION_NONE, NULL },
+    { (char*) "sum even array", test_sum_even, NULL, NULL, MUNIT_TEST_OPTION_NONE, NULL },
+    { (char*) "bit count", test_bit_count, NULL, NULL, MUNIT_TEST_OPTION_NONE, NULL },
+    { NULL, NULL, NULL, NULL, MUNIT_TEST_OPTION_NONE, NULL }
+};
 
 static const MunitSuite test_suite = {
-	//FILL ME
+        (char*) "", 
+        test_suite_tests, 
+        NULL, // Вложенные наборы тесtov
+        1, // Количество прогонов
+        MUNIT_SUITE_OPTION_NONE 
 };
 
+
 int
 main(int argc, const char *argv[])
 {
-	munit_suite_main(&test_suite, (void *) "string library test", argc, (char * const*) argv);
-	return 0;
+        munit_suite_main(&test_suite, (void *) "auxiliary library test", argc, (char * const*) argv);
+        return 0;
 }
-