func_code_string: #include <bits/stdc++.h>   using namespace std;   long long n, i, j, ans, sum1, sum2;   long long x[100000], y[100000];   int main() {     scanf( %I64d , &n);     sum1 = 0;     sum2 = 0;     ans = 0;     for (i = 0; i < n; i++) {       scanf( %I64d %I64d , &x[i], &y[i]);       ans += (n * (x[i] * x[i] + y[i] * y[i]));       sum1 += x[i];       sum2 += y[i];     }     ans -= (sum1 * sum1);     ans -= (sum2 * sum2);     printf( %I64d n , ans);     return 0;   }   