func_code_string: #include <bits/stdc++.h>   using namespace std;   long long int MOD = 1000000007;   long long int power(long long int x, long long int y, long long int p) {     long long int res = 1;     x = x % p;     if (x == 0) return 0;     while (y > 0) {       if (y & 1) res = (res * x) % p;       y = y >> 1;       x = (x * x) % p;     }     return res;   }   int main() {     ios::sync_with_stdio(false);     cin.tie(NULL);     ;     long long int t;     t = 1;     while (t--) {       long long int n, m, k;       cin >> n >> m >> k;       vector<long long int> xs, ys;       for (long long int i = 0; i < n * m; i++) {         ys.push_back(i / n + 1);         if ((i / n) % 2 == 0) {           xs.push_back(i % n + 1);         } else {           xs.push_back(n - i % n);         }       }       for (long long int i = 0; i < k - 1; i++) {         cout << 2 <<     << xs[2 * i] <<     << ys[2 * i] <<     << xs[2 * i + 1]              <<     << ys[2 * i + 1] << endl;       }       cout << n * m - 2 * (k - 1) <<    ;       for (long long int i = 2 * (k - 1); i < n * m; i++) {         cout << xs[i] <<     << ys[i] <<    ;       }     }   }   