func_code_string: #include <bits/stdc++.h>   using namespace std;   vector<pair<int, int> > snakeG(int x1, int y1, int x2, int y2) {     vector<pair<int, int> > res;     int n = y2 - y1 + 1, m = x2 - x1 + 1;     for (int i = 0; i < m; ++i) {       for (int j = 0; j < n; ++j) {         if (i % 2 == 0) {           res.push_back(make_pair(x1 + i, y1 + j));         } else {           res.push_back(make_pair(x1 + i, y2 - j));         }       }     }     return res;   }   vector<pair<int, int> > snakeV(int x1, int y1, int x2, int y2) {     vector<pair<int, int> > res;     int n = y2 - y1 + 1, m = x2 - x1 + 1;     for (int j = 0; j < n; ++j) {       for (int i = 0; i < m; ++i) {         if (j % 2 == 0) {           res.push_back(make_pair(x1 + i, y1 + j));         } else {           res.push_back(make_pair(x2 - i, y1 + j));         }       }     }     return res;   }   int main() {     int n, m;     cin >> n >> m;     if (m == 1) {       if (n == 2) {         cout << 0 << endl;         cout << 1 <<     << 1 << endl;         cout << 2 <<     << 1 << endl;         cout << 1 <<     << 1 << endl;         return 0;       } else {         cout << 1 << endl;         cout << n <<     << m <<     << 1 <<     << 1 << endl;         for (int i = 1; i < n + 1; ++i) cout << i <<     << 1 << endl;         cout << 1 <<     << 1 << endl;         return 0;       }     }     if (n == 1) {       if (m == 2) {         cout << 0 << endl;         cout << 1 <<     << 1 << endl;         cout << 1 <<     << 2 << endl;         cout << 1 <<     << 1 << endl;         return 0;       } else {         cout << 1 << endl;         cout << n <<     << m <<     << 1 <<     << 1 << endl;         for (int i = 1; i < m + 1; ++i) cout << 1 <<     << i << endl;         cout << 1 <<     << 1 << endl;         return 0;       }     }     if (n == m) {       if (n % 2 == 0) {         cout << 0 << endl;         vector<pair<int, int> > res = snakeG(1, 2, n, m);         cout << 1 <<     << 1 << endl;         for (int i = 0; i < res.size(); ++i)           cout << res[i].first <<     << res[i].second << endl;         for (int i = n; i >= 1; --i) cout << i <<     << 1 << endl;       } else {         cout << 1 << endl;         cout << n <<     << m <<     << 1 <<     << 1 << endl;         vector<pair<int, int> > res = snakeG(1, 1, n, m);         for (int i = 0; i < res.size(); ++i)           cout << res[i].first <<     << res[i].second << endl;         cout << 1 <<     << 1 << endl;       }     } else {       if (n > m) {         if (m % 2 == 0) {           if (n % 2 == 0) {             cout << 0 << endl;             vector<pair<int, int> > res = snakeG(1, 2, n, m);             cout << 1 <<     << 1 << endl;             for (int i = 0; i < res.size(); ++i)               cout << res[i].first <<     << res[i].second << endl;             for (int i = n; i >= 1; --i) cout << i <<     << 1 << endl;           } else {             cout << 0 << endl;             vector<pair<int, int> > res = snakeG(1, 2, n - 2, m);             vector<pair<int, int> > res1 = snakeV(n - 1, 1, n, m);             reverse(res1.begin(), res1.end());             cout << 1 <<     << 1 << endl;             for (int i = 0; i < res.size(); ++i)               cout << res[i].first <<     << res[i].second << endl;             for (int i = 0; i < res1.size(); ++i)               cout << res1[i].first <<     << res1[i].second << endl;             for (int i = n - 2; i >= 1; --i) cout << i <<     << 1 << endl;           }         } else {           if (n % 2 == 0) {             cout << 0 << endl;             vector<pair<int, int> > res = snakeG(1, 2, n, m);             cout << 1 <<     << 1 << endl;             for (int i = 0; i < res.size(); ++i)               cout << res[i].first <<     << res[i].second << endl;             for (int i = n; i >= 1; --i) cout << i <<     << 1 << endl;           } else {             cout << 1 << endl;             cout << n <<     << m <<     << 1 <<     << 1 << endl;             vector<pair<int, int> > res = snakeG(1, 1, n, m);             for (int i = 0; i < res.size(); ++i)               cout << res[i].first <<     << res[i].second << endl;             cout << 1 <<     << 1 << endl;           }         }       } else {         if (n % 2 == 0) {           cout << 0 << endl;           vector<pair<int, int> > res = snakeG(1, 2, n, m);           cout << 1 <<     << 1 << endl;           for (int i = 0; i < res.size(); ++i)             cout << res[i].first <<     << res[i].second << endl;           for (int i = n; i >= 1; --i) cout << i <<     << 1 << endl;         } else {           if (m % 2 == 0) {             cout << 0 << endl;             vector<pair<int, int> > res = snakeG(1, 2, n - 2, m);             vector<pair<int, int> > res1 = snakeV(n - 1, 1, n, m);             reverse(res1.begin(), res1.end());             cout << 1 <<     << 1 << endl;             for (int i = 0; i < res.size(); ++i)               cout << res[i].first <<     << res[i].second << endl;             for (int i = 0; i < res1.size(); ++i)               cout << res1[i].first <<     << res1[i].second << endl;             for (int i = n - 2; i >= 1; --i) cout << i <<     << 1 << endl;           } else {             cout << 1 << endl;             cout << n <<     << m <<     << 1 <<     << 1 << endl;             vector<pair<int, int> > res = snakeG(1, 1, n, m);             for (int i = 0; i < res.size(); ++i)               cout << res[i].first <<     << res[i].second << endl;             cout << 1 <<     << 1 << endl;           }         }       }     }     return 0;   }   