#include<bits/stdc++.h>
using namespace std;
typedef __int128 ll;
ll n,a[15],b[15],p=1,ans=0;
inline ll read()
{
    ll x=0,f=1;
    char ch=getchar();
    while(ch<'0'||ch>'9')
    {
        if(ch=='-')f=-1;
        ch=getchar();
    }
    while(ch>='0'&&ch<='9')
    {
        x=(x<<1)+(x<<3)+ch^48;
        ch=getchar();
    }
    return x*f;
}
inline void write(ll a)
{
    if(a<0)
    {
        putchar('-');
        a=-a;
    }
    if(a>9)write(a/10);
    putchar(a%10+'0');
}
int main(){
    freopen("ccyz.in","r",stdin);
    freopen("ccyz.out","w",stdout);
    n=read();
    for(int i=1;i<=n;i++)
    {
        a[i]=read();
        b[i]=read();
    }
    for(int i=n;i>=1;i--)
    {
        while(ans%a[i]!=b[i])
            ans+=p;
        p*=a[i];
    }
    write(ans);
    puts("");
    return 0;
}