#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define ll long long
bool sortbysec(const pair<int,int> &a,
              const pair<int,int> &b)
{
    return ((a.first-a.second) > (b.first-b.second));
}
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	int n;
	cin >> n;
	vector<pair<ll,ll>> a,b;
	for(int i=0;i<n;i++)
	{
		int x,y;
		cin >> x >> y;
		b.push_back(make_pair(x,y));
	}
	sort(b.begin(),b.end(),sortbysec);
	ll sum=0;
	for(int i=0;i<n;i++)
	{
		sum+=b[i].first*i+b[i].second*(n-(i+1));
	}
	cout << sum << endl;
	return 0;
}