#include <iostream>
using namespace std;
typedef pair<int, int>PII;
PII d[15];
int t;
int ans;
void dfs(int m,int s,int k,int st,int n) {
	if (m == n) {
		ans = min(ans, abs(s-k));
		return;
	}
	for (int i = st; i <= t; i++) {
		dfs(m + 1, s * d[i].first, k + d[i].second, i + 1, n);
	}
}
int main() {
	cin >> t;
	for (int i = 1; i <= t; i++) {
		int a, b;
		cin >> a >> b;
		d[i].first = a;
		d[i].second = b;
	}
	ans = 0x3f3f3f3f;
	
	for (int i = 1; i <= t; i++) {
		dfs(0, 1, 0, 1, i);
	}
	
	cout << ans << endl;
	return 0;
}