diff --git a/task_01/src/main.cpp b/task_01/src/main.cpp
index 0e4393b..066f6ce 100644
--- a/task_01/src/main.cpp
+++ b/task_01/src/main.cpp
@@ -1,3 +1,11 @@
 #include <iostream>
-
-int main() { return 0; }
+#include <algorithm>
+using namespace std;
+int main() { 
+    int a[3];
+    cin>>a[0]>>a[1]>>a[2];
+    sort(begin(a), end(a));
+    int c;
+    cout<<a[1];
+    cin.get();
+    return 0; }
diff --git a/task_01/src/median.cpp b/task_01/src/median.cpp
new file mode 100644
index 0000000..49b2e4e
--- /dev/null
+++ b/task_01/src/median.cpp
@@ -0,0 +1,5 @@
+#include<median.h>
+int median(int a[3]){
+    sort(begin(a), end(a));
+    return a[1];
+}
\ No newline at end of file
diff --git a/task_01/src/median.h b/task_01/src/median.h
new file mode 100644
index 0000000..20b3e4a
--- /dev/null
+++ b/task_01/src/median.h
@@ -0,0 +1,2 @@
+#include <algorithm>
+int median( int a[3]);
\ No newline at end of file
diff --git a/task_01/src/test.cpp b/task_01/src/test.cpp
index 0c33b55..c0a74ed 100644
--- a/task_01/src/test.cpp
+++ b/task_01/src/test.cpp
@@ -1,5 +1,5 @@
 #include <gtest/gtest.h>
-
+#include <median.h>
 #include <sum.hpp>
 
-TEST(Test, Simple) { ASSERT_EQ(Sum(1, 2, 3), 6); }
\ No newline at end of file
+TEST(Test, Simple) {ASSERT_EQ(median({1, 6, 4}), 4);}
\ No newline at end of file
diff --git a/task_02/src/get_max.cpp b/task_02/src/get_max.cpp
new file mode 100644
index 0000000..93d2594
--- /dev/null
+++ b/task_02/src/get_max.cpp
@@ -0,0 +1,11 @@
+#include <get_max.h>
+int get_max(int* a, int size)
+{
+    int max_el = a[0];
+    for (int i = 0; i < size; i++)
+    {
+        if (a[i] > max_el)
+            max_el = a[i];
+    }
+    return max_el;
+}
\ No newline at end of file
diff --git a/task_02/src/get_max.h b/task_02/src/get_max.h
new file mode 100644
index 0000000..cb0bdba
--- /dev/null
+++ b/task_02/src/get_max.h
@@ -0,0 +1 @@
+int get_max(int* a, int size);
\ No newline at end of file
diff --git a/task_03/src/invert_array.cpp b/task_03/src/invert_array.cpp
new file mode 100644
index 0000000..b10551d
--- /dev/null
+++ b/task_03/src/invert_array.cpp
@@ -0,0 +1,10 @@
+#include <invert_array.h>
+void invert_array(int* a, int size)
+{
+    for (int i = 0; i < size/2; i++)
+    {
+        int tmp = a[i];
+        a[i] = a[size - i - 1];
+        a[size - i] = tmp;
+    }
+}
\ No newline at end of file
diff --git a/task_03/src/invert_array.h b/task_03/src/invert_array.h
new file mode 100644
index 0000000..093110f
--- /dev/null
+++ b/task_03/src/invert_array.h
@@ -0,0 +1 @@
+void invert_array(int* a, int size);
\ No newline at end of file
diff --git a/task_03/src/test.cpp b/task_03/src/test.cpp
index 2d868db..bf0e47b 100644
--- a/task_03/src/test.cpp
+++ b/task_03/src/test.cpp
@@ -1,6 +1,13 @@
 
 #include <gtest/gtest.h>
 
-#include "reverse.hpp"
+#include "invert_array.h"
 
-TEST(Reverse, Simple) {}
+int test_in[]={1, 2, 3, 4, 5};
+int test_out[] = {5, 4, 3, 2, 1};
+invert(test_in, 5);
+TEST(Reverse, Simple) {
+    for(i=0; i<5; i++){
+    ASSERT_EQ(test_in[i], test_out[i]);
+    }
+    }
diff --git a/task_04/src/shift_array.cpp b/task_04/src/shift_array.cpp
new file mode 100644
index 0000000..d150ddc
--- /dev/null
+++ b/task_04/src/shift_array.cpp
@@ -0,0 +1,17 @@
+#include <shift_array.h>
+void shift_array(int* a, int size, int N)
+{
+    int tmp = a[size - 1];
+    int* buff = new int[N];
+    for (int i = size - N; i < size; i++)
+        buff[i - size + N] = a[i];
+    for (int i = size - 1; i >= 0; i--)
+    {
+        a[i] = a[(i + N) % size];
+    }
+    for (int i = 0; i < N; i++)
+    {
+        a[i] = buff[i];
+    }
+    delete buff;
+}
\ No newline at end of file
diff --git a/task_04/src/shift_array.h b/task_04/src/shift_array.h
new file mode 100644
index 0000000..04094bd
--- /dev/null
+++ b/task_04/src/shift_array.h
@@ -0,0 +1 @@
+void shift_array(int* a, int size, int N);
\ No newline at end of file
diff --git a/task_04/src/test.cpp b/task_04/src/test.cpp
index 5e11617..59f4680 100644
--- a/task_04/src/test.cpp
+++ b/task_04/src/test.cpp
@@ -1,6 +1,7 @@
 
 #include <gtest/gtest.h>
-
-TEST(TopologySort, Simple) {
-  ASSERT_EQ(1, 1);  // Stack []
-}
+#include <shift_array.h>
+int a[] = {1, 2, 3, 4, 5};
+TEST(Shift, Simple) {
+    ASSERT_EQ(get_max(a, 5), 5);
+    }
\ No newline at end of file