func_code_string: #include <bits/stdc++.h>   using namespace std;   int m, n, x, y;   int ABS(int x) { return (x < 0) ? (-x) : (x); }   int main() {     scanf( %d%d%d%d , &m, &x, &n, &y);     if (m > n) {       swap(m, n);       swap(x, y);     }     int d = ABS(x - y);     long long ans = 1 + m + n;     for (int i = 1; i <= m; i++) {       int b = i + d - 1, a = ABS(d - i) + 1;       a = max(a, 1);       b = min(b, n);       if (a <= b) ans += (b - a + 1) * 2 - 1;       if (i > d) ans++;     }     cout << ans << endl;     return 0;   }   