#include <bits/stdc++.h>
#define int long long
#define endll '\n';
#define pb push_back
#define all(v) v.begin(), v.end()
using namespace std;

const int mod = 1e9 + 7, N = 1e6;
unordered_map<int, int> vis;

void solve()
{

   vis.clear();
   int n, k;
   cin >> n >> k;
   int L = 0, R = k / n;
   int ans = 0;
   while(L <= R) {
      int M = (L + R) / 2;
      int value  = M, K = k - (M * n);
      if(value > K) {
         R = M - 1;
      }
      else {
         ans = max (ans, value * K);
         L = M + 1;
      }
   }

   cout << ans << endll;


}

int32_t main()
{
   ios::sync_with_stdio(false);
   cin.tie(0);
   int t = 1;
   cin >> t;
   while (t--)
   {
      solve();
   }
   return 0;
}