#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <ctime>
#include <cassert>
#include <iostream>
#include <cctype>
#include <sstream>
#include <string>
#include <list>
#include <vector>
#include <queue>
#include <set>
#include <stack>
#include <map>
#include <utility>
#include <numeric>
#include <algorithm>
#include <iterator>
#include <bitset>
#include <complex>
#include <fstream>
using namespace std;
typedef long long ll;
const double EPS = 1e-9;
typedef vector<int> vint;
typedef pair<int, int> pint;
#define rep(i, n) REP(i, 0, n)
#define ALL(v) v.begin(), v.end()
#define MSG(a) cout << #a << " " << a << endl;
#define REP(i, x, n) for(int i = x; i < n; i++)
template<class T> T RoundOff(T a){ return int(a+.5-(a<0)); }
template<class T, class C> void chmax(T& a, C b){ if(a < b) a = b; }
template<class T, class C> void chmin(T& a, C b){ if(b < a) a = b; }
template<class T, class C> pair<T, C> mp(T a, C b){ return make_pair(a, b); }

struct M{ int a, b; };

int main()
{
    int n;
	cin >> n;
	
	vector<M> v(n);
	rep(i, n) cin >> v[i].a >> v[i].b;
	
	int res = 0;
	rep(i, n - 1)
	{
		int A = 0, B = 1;
		rep(j, n - i) if(v[A].a < v[j].a)
		{
			A = j;
		}
		
		rep(j, n - i) if(A != j && v[B].b < v[j].b)
		{
			B = j;
		}
		
		res += v[A].a * v[A].b * v[B].a * v[B].b;
		
		v[A].a = v[B].a;
		
		v.erase(v.begin() + B);
	}
	
	cout << res << endl;
}