diff --git a/CMakeLists.txt b/CMakeLists.txt
index ca1e4ae..d3d97c7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.0)
 project(task1)
 
-set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_AUTOMOC ON)
 set(CMAKE_AUTORCC ON)
 set(CMAKE_AUTOUIC ON)
diff --git a/task1/mergesort.h b/task1/mergesort.h
index c798079..b81af53 100644
--- a/task1/mergesort.h
+++ b/task1/mergesort.h
@@ -6,6 +6,7 @@
 #include <mutex>
 #include <future>
 #include <ranges>
+#include <span>
 
 namespace algo {
 
@@ -332,10 +333,10 @@ namespace algo {
             std::advance(mid, std::distance(data.begin(), data.end()) / 2);
 
 
-
-
-            std::vector<T> left(std::make_move_iterator(data.begin()), std::make_move_iterator(mid));
-            std::vector<T> right(std::make_move_iterator(mid), std::make_move_iterator(data.end()));
+            std::span<T> left(data.begin(), mid);
+            std::span<T> right(mid, data.end());
+            //std::vector<T> left(std::make_move_iterator(data.begin()), std::make_move_iterator(mid));
+            //std::vector<T> right(std::make_move_iterator(mid), std::make_move_iterator(data.end()));
 
             if (depth < num_threads) {
                 std::thread left_thread([&]() { split(left, outdata, cmp, depth + 1, num_threads, mut); });