#include <bits/stdc++.h>

using namespace  std;
int n,s[12],b[12],pd[12],k = 0;
int ans = 0x7f;

void search(int t,int ss,int bb) {
	//int zs = ss,zb = bb,;
	
	if(t > n) {
		if(ss == 1 && bb == 0) return;
		else {
			ans = min(abs(ss-bb),ans);
			return;
		}
	}
	search(t+1,ss*s[t],bb+b[t]);
	search(t+1,ss,bb);
}
int main() {
	scanf("%d", &n);
	s[0] = 1;
	for(int i = 1; i <= n; i++) scanf("%d %d", &s[i], &b[i]);
	search(1,s[1],b[1]);
	printf("%d", ans);
	return 0;
}