func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 1e5 + 10;   long long x[maxn], y[maxn];   int main() {     ios::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     ;     long long n;     cin >> n;     long long s = 0, sx = 0, sy = 0;     for (int i = 0; i < n; i++) {       cin >> x[i] >> y[i];       sx += x[i];       sy += y[i];       s += (n - 1) * (x[i] * x[i]) + (n - 1) * (y[i] * y[i]);     }     for (int i = 0; i < n; i++) {       s -= ((x[i] * (sx - x[i])) + (y[i] * (sy - y[i])));     }     cout << s;     return 0;   }   