#include<bits/stdc++.h>
using namespace std;
#define ll long long
void solve() {
    ll n, k;
    cin >> n >> k;

    ll l = 0, r = k/n, ans = 0;

    while(l <= r){
        ll mid = (l + r)/2;

        ll total_op = mid * n;

        if(total_op <= k){
            ans = mid;
            l = mid + 1;
        }
        else {
            r = mid - 1;
        }
    }
    ll rem = k - (n * ans);


    cout << ans * rem << '\n';
}
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int t = 1;
    cin >> t;
    while(t--){
        solve();
    }
    return 0;
}