#include <bits/stdc++.h>
#define IOS ios::sync_with_stdio(false)
#define endl '\n'
using namespace std;
typedef long long ll;
int T;
ll n, m;
int main()
{
IOS; cin.tie(0), cout.tie(0);
cin >> T;
while (T--)
{
ll ans = 1e9;
cin >> n >> m;
if (n >= m)
cout << n - m << endl;
else
{
for (int l = 1, r; l <= n; l = r + 1)
{
r = (m - 1) / ((m - 1) / l);
if (r > n)
{
ans = min(ans, n - m + ((m - 1) / l) * l);
}
else
{
ans = min(ans, n - m + ((m - 1) / l) * l);
}
}
cout << ans << endl;
}
}
return 0;
}