diff --git a/task_01/src/search_task.cpp b/task_01/src/search_task.cpp
new file mode 100644
index 00000000..b106d6a9
--- /dev/null
+++ b/task_01/src/search_task.cpp
@@ -0,0 +1,21 @@
+#include "search_task.hpp"
+
+#include <algorithm>
+#include <optional>
+
+std::optional<std::pair<LL, LL>> SearchInList(std::vector<LL> list, LL n) {
+  if (list.empty()) return std::nullopt;
+  if (!std::is_sorted(list.cbegin(), list.cend())) return std::nullopt;
+  LL left = 0;
+  LL right = list.size() - 1;
+  while (left != right) {
+    LL sum = list[left] + list[right];
+    if (sum == n)
+      return std::pair<LL, LL>{list[left], list[right]};
+    else if (sum < n)
+      left++;
+    else if (sum > n)
+      right--;
+  }
+  return std::nullopt;
+}
\ No newline at end of file
diff --git a/task_01/src/search_task.hpp b/task_01/src/search_task.hpp
new file mode 100644
index 00000000..96db6d98
--- /dev/null
+++ b/task_01/src/search_task.hpp
@@ -0,0 +1,9 @@
+#pragma once
+
+#include <iostream>
+#include <optional>
+#include <vector>
+
+typedef long long LL;
+
+std::optional<std::pair<LL, LL>> SearchInList(std::vector<LL> list, LL n);
\ No newline at end of file
diff --git a/task_01/src/test.cpp b/task_01/src/test.cpp
index ef5a86ae..330c46f2 100644
--- a/task_01/src/test.cpp
+++ b/task_01/src/test.cpp
@@ -1,8 +1,27 @@
-
 #include <gtest/gtest.h>
 
-#include "topology_sort.hpp"
+#include <optional>
+
+#include "search_task.hpp"
 
-TEST(TopologySort, Simple) {
-  ASSERT_EQ(1, 1);  // Stack []
-}
+TEST(SearchInList, Simple) {
+  std::vector<LL> list = {2, 4, 7, 9, 12, 16, 19, 23, 27};
+  ASSERT_EQ(SearchInList(list, 50), std::pair(23LL, 27LL));
+  ASSERT_EQ(SearchInList(list, 43), std::pair(16LL, 27LL));
+  ASSERT_EQ(SearchInList(list, 21), std::pair(2LL, 19LL));
+  ASSERT_EQ(SearchInList(list, 18), std::pair(2LL, 16LL));
+  ASSERT_EQ(SearchInList(list, 11), std::pair(2LL, 9LL));
+  ASSERT_EQ(SearchInList(list, 47), std::nullopt);
+  ASSERT_EQ(SearchInList(list, 24), std::nullopt);
+  ASSERT_EQ(SearchInList(list, 2), std::nullopt);
+  ASSERT_EQ(SearchInList(list, 1), std::nullopt);
+  ASSERT_EQ(SearchInList(list, -1421532541), std::nullopt);
+  list = {};
+  ASSERT_EQ(SearchInList(list, 10), std::nullopt);
+  list = {1};
+  ASSERT_EQ(SearchInList(list, 100), std::nullopt);
+  list = {0};
+  ASSERT_EQ(SearchInList(list, -142), std::nullopt);
+  list = {};
+  ASSERT_EQ(SearchInList(list, 0), std::nullopt);
+}
\ No newline at end of file
diff --git a/task_01/src/topology_sort.cpp b/task_01/src/topology_sort.cpp
deleted file mode 100644
index e53f670c..00000000
--- a/task_01/src/topology_sort.cpp
+++ /dev/null
@@ -1 +0,0 @@
-#include "topology_sort.hpp"
diff --git a/task_01/src/topology_sort.hpp b/task_01/src/topology_sort.hpp
deleted file mode 100644
index 6f70f09b..00000000
--- a/task_01/src/topology_sort.hpp
+++ /dev/null
@@ -1 +0,0 @@
-#pragma once