func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n;     scanf( %d , &n);     long long ans = 0;     vector<pair<int, int> > v;     vector<int> all;     for (int i = 1; i <= n; ++i) {       int a, b, c, d;       scanf( %d%d%d%d , &a, &b, &c, &d);       if (a + b < c + d) {         if (a > d) v.push_back(make_pair(a - d, d - a));         if (b > c) v.push_back(make_pair(c - b, b - c));       } else {         v.push_back(make_pair(a, b));         v.push_back(make_pair(c, d));       }     }     for (auto p : v) {       int a = p.first, b = p.second;       all.push_back(a + b);       ans += a - b;     }     sort(all.begin(), all.end(), greater<int>());     for (int i = 0; i < (int)all.size(); ++i) {       if (i & 1)         ans -= all[i];       else         ans += all[i];     }     printf( %lld n , ans / 2);     return 0;   }   