#include<bits/stdc++.h>
using namespace std;
int a[15],b[15],n,ans=0x7f;
void dfs(int i,int x,int y)
{
	if(i>n)
	{
		if(x==1&&y==0) return;
		ans=min(abs(x-y),ans);
		return;
	}
	dfs(i+1,x*a[i],y+b[i]);
	dfs(i,x,y);
}
int main()
{
	cin>>n;
	for(int i=1;i<=n;i++) scanf("%d%d",&a[i],&b[i]);
	dfs(1,1,0);
	cout<<ans<<endl;
	return 0;
}