#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, M);
         L = M + 1;
      }
   }

   for (int i = max(0LL, ans - 100); i <= ans + 100; i++)
   {
      int value = i, K = k - (i * n);
      if (K <= 0)
         continue;
      ans = max(ans, value * K);
   }

   cout << ans << endll;
}

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