#include<bits/stdc++.h>
using namespace std;

void solve()
{
    int a,b,gcd,lcm;
    cin>>a>>b;
    for(int i=1; i<=a && i<=b; i++){
        if(a%i==0 && b%i==0){
            gcd=i;
        }
    }
    lcm=a*b/gcd;
    int ans=lcm-min(a,b);
   cout<<ans<<endl;
}

int main()
{
    int t; cin>>t;
    while(t--)
    solve();
}