#include <vector>

vector<vector<int>> a = { { 9, 2, 7, 4, 5 },{ 5, 6, 5, 8, 5 },{ 3, 2, 18, 1, 2 },{ 1, 6, 3, 7, 8 } };
vector<vector<int>> b = { { 1, 2, 3, 4, 5, 4, 5 },{ 4, 4, 5, 3, 5, 6, 4 },{ 1, 5, 5, 5, 3, 6, 7 },{ 1, 3, 3, 3, 3, 0, 9 },{ 3, 4, 5, 6, 7, 7, 7 } };
auto res_a = a;
auto res_b = b;