#include <bits/stdc++.h>
#define int long long
#define pb push_back
#define pii pair<int, int>

using namespace std;
double pi = acos(-1);
const int N = 2e5 + 10;
int n;
pii a[N];
bool cmp(pii x, pii y)
{
	double al, be;
	al = (x.second*y.first);
	be = (y.second* x.first);
	return al > be;
}
main()
{
	cin >> n;
	for(int i = 0; i < n; i++) cin >> a[i].first >> a[i].second;

	sort(a, a + n, cmp);
	int mx = -1;
	bool ok = 0;
	int l = 0;
	int cur = 0;
	int cx = 0, cy = 0;
	for(int i = 0; i < n; i++)
	{

		cy += a[i].second;
		cur += (l + cy) * a[i].first;
		if(abs(cur) > mx)
		{
			mx = abs(cur);
			if(cur < 0)
			{
				ok = 1;
			} else ok = 0;
 		}
		l = cy;

	}
	if(ok) cout << "-";
	cout << mx;
}