#include<bits/stdc++.h>
int main() {
    long long n, a, b, ans = 0, gcd = 1;
    scanf("%lld", &n);
    for(int i = 1; i <= n; i++) {
        scanf("%lld %lld", &a, &b);
        if(i == 1) ans = b;
        while(ans % a != b)
            ans += gcd;
        gcd *= a;
    }
    printf("%lld", ans);
}

AC记录