#include <bits/stdc++.h>
using namespace std;
using ll = long long;
void solve() {
	ll a, b;
	cin >> a >> b;
	ll r=0ll, l=a;
	while (r<l-1) {
		ll n = (r+l)/2;
		if ((a-n+1)*(n-1) < (a-b-n+1)*n) {
			r = n;
		}
		else {
			l = (n-1);
		}
	}
	ll n = l;
	if ((a-n+1)*(n-1) < (a-b-n+1)*n) {
	  cout << l << endl;
	}
	else {
	  cout << r << endl;
	}
	return;
}
int main() {
	int t;
	cin >> t;
	while (t--) {
		solve();
	}
}