func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, x, m, y;   int main() {     int i, j, k, flag;     long long ans;     int l1, l2, r1, r2, l, r;     int cnt;     while (scanf( %d%d%d%d , &n, &x, &m, &y) != EOF) {       if (x > y) {         k = x;         x = y;         y = k;       }       ans = 1;       flag = 0;       for (i = 1; i <= n; i++) {         k = ans;         if (i + x == y) {           r1 = y - x + i;           r = min(r1, m);           cnt = 0;           if (r1 <= r) {             cnt++;           }           ans += 2 * (r - cnt) + cnt;           flag = 1;         } else if (i + x > y) {           l1 = i + x - y;           r1 = y - x + i;           if (m < l1) {             ans++;             continue;           }           r = min(r1, m);           cnt = 1;           if (r1 <= r) {             cnt++;           }           ans += (r - l1 + 1 - cnt) * 2 + cnt;           flag = 1;         } else {           l1 = y - x - i;           r1 = y - x + i;           if (m < l1) {             ans++;             continue;           }           cnt = 1;           r = min(r1, m);           if (r1 <= r) {             cnt++;           }           ans += 2 * (r - l1 + 1 - cnt) + cnt;           flag = 1;         }       }       for (i = 1; i <= m; i++) {         if (i + x == y) {           continue;         } else if (i + x > y) {           l1 = i + x - y;           r1 = y - x + i;           if (n < l1) {             ans++;           }         } else {           l1 = y - x - i;           r1 = y - x + i;           if (n < l1) {             ans++;             continue;           }         }       }       if (flag) ans++;       cout << ans << endl;     }     return 0;   }   