func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n, m, x, y;     cin >> n >> m >> x >> y;     vector<vector<int>> chessboard(n, vector<int>(m));     for (int i = 0; i < n; i++)       for (int j = 0; j < m; j++) chessboard[i][j] = 0;     cout << x <<     << y << endl;     chessboard[x - 1][y - 1] = 1;     if (chessboard[0][y - 1] == 0) cout << 1 <<     << y << endl;     chessboard[0][y - 1] = 1;     if (chessboard[0][0] == 0) cout << 1 <<     << 1 << endl;     chessboard[0][0] = 1;     int j = 0;     for (int i = 0; i < n; i++) {       if (j == m) j--;       if (j < 0) j++;       bool plus = (j == 0);       while (j >= 0 && j < m) {         if (chessboard[i][j] == 0) {           cout << i + 1 <<     << j + 1 << endl;           chessboard[i][j] = 1;         }         (plus) ? j++ : j--;       }     }     return 0;   }   