e

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <cctype>
#include <iostream>
#include <vector>

using namespace std;

#define maxn (200000)
#define ll long long
#define ull unsigned long long
#define PB(x) push_back(x)
#define MP(x,y) make_pair(x,y)

ll x[maxn],y[maxn];
int n;
ll sumx,sumy,sumx2,sumy2,N;

int main(){
    scanf("%d",&n); N=n;
    for (int i=1;i<=n;i++) {
        int a,b; scanf("%d%d",&a,&b);
        x[i]=a; y[i]=b;
    }

    for (int i=1;i<=n;i++) sumx+=x[i];
    for (int i=1;i<=n;i++) sumy+=y[i];
    for (int i=1;i<=n;i++) sumx2+=x[i]*x[i];
    for (int i=1;i<=n;i++) sumy2+=y[i]*y[i];

    cout << ((-2ll*sumx*sumx+2ll*N*sumx2) + (-2ll*sumy*sumy+2ll*N*sumy2))/2ll << endl;

    return 0;
}