func_code_string: #include <bits/stdc++.h>   using namespace std;   vector<pair<long long, int> > v;   int n;   long long A[100005];   long long B[100005];   int main() {     scanf( %d , &n);     for (int i = 1; i <= n; i++) {       int a, b;       scanf( %d %d , &a, &b);       A[i] = (long long)a;       B[i] = (long long)b;       v.push_back(make_pair((long long)(b - a), i));     }     sort(v.begin(), v.end());     long long ans = 0;     for (int i = 1; i <= n; i++) {       long long a = A[v[i - 1].second];       long long b = B[v[i - 1].second];       ans += a * ((long long)(i - 1)) + b * ((long long)(n - i));     }     printf( %lld n , ans);     return 0;   }   