func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, m;   int main() {     ios_base::sync_with_stdio(false);     cin >> n >> m;     if (m == 3 && n != 4 && n != 3) {       cout << -1;       return false;     }     int x = 0, y = 0;     for (int i = 1; i <= m; i++) {       cout << x <<     << y << endl;       x++;       y += i;     }     x = 1000000, y = 0;     for (int i = 1; i <= n - m; i++) {       cout << x <<     << y << endl;       x--;       y += i;     }   }   