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

void solve()
{
    int n, k; cin>>n>>k;
    int a=k/(n+1);
    int ans=a*(k-(n*a));
    //cout<<a<<endl;
    cout<<ans<<endl;

}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    int test = 1;
    cin >> test;
    for (int tc = 0; tc < test; ++tc)
    {
        solve();
    }

    return 0;
}