#include<bits/stdc++.h>
using namespace std;
struct as{
int s,b;
}a[50];
int main(){
int n;
cin>>n;
for(int i=1;i<=n;i++)cin>>a[i].s>>a[i].b;
int minsb=2e9;
for(int i=1;i<=n;i++){
int sf=a[i].s;
int bf=a[i].b;
minsb=min(minsb,abs(sf-bf));
for(int j=i+1;j<=n;j++){
sf*=a[j].s;
bf+=a[j].b;
minsb=min(minsb,abs(sf-bf));
}
}
cout<<minsb;
}
