#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

int main(int argc, char **argv) {
	int T;
	scanf("%d", &T);
	while (T-- != 0) {
		ll n, a;
		scanf("%lld%lld", &n, &a);
		ll tot = 2 * n * (a - 1), lo = 0, hi = n - 1;
		while (lo < hi) {
			ll mid = (lo + hi + 1) / 2;
			if (mid * (mid + 1) <= tot)
				lo = mid;
			else
				hi = mid - 1;
		}
		printf("%lld\n", lo + 1);
	}
	return 0;
}