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

typedef long long Int;
typedef pair<int,int> PII;
typedef vector<int> VInt;
 
#define FOR(i, a, b) for(i = (a); i < (b); ++i)
#define RFOR(i, a, b) for(i = (a) - 1; i >= (b); --i)
#define EACH(it, a) for(auto it = (a).begin(); it != (a).end(); ++it)
#define CLEAR(a, b) memset(a, b, sizeof(a))
#define SIZE(a) int((a).size())
#define ALL(a) (a).begin(),(a).end()
#define MP make_pair

int gcd(int a, int b)
{
	return a == 0 ? b : gcd(b % a, a);
}

double dist(double a, double b)
{
	return sqrt(a*a + b*b);
}

double f(double best, int n, int m, int r, int c)
{
	if(r < 0 || n < r) return best;
	if(c < 0 || m < c) return best;
	if(r == 0 && c == 0) return best;
	if(r == n && c == m) return best;
	if(r == n - r && c == m - c) return best;
	if(gcd(r, c) != 1) return best;
	if(gcd(n - r, m - c) != 1) return best;
	return min(best, dist(r, c) + dist(n - r, m - c));
}

double f(int n, int m)
{
	if(gcd(n, m) == 1) return dist(n, m);
	int i, j;
	double inf = 1e47;
	double res = inf;
	FOR(i, 0, n + 1)
	{
		Int t = i;
		t *= m;
		t /= n;
		FOR(j, 0, 2)
		{
			int c = int(t) + j;
			res = f(res, n, m, i, c);
		}
	}
	FOR(i, 0, m + 1)
	{
		Int t = i;
		t *= n;
		t /= m;
		FOR(j, 0, 2)
		{
			int r = int(t) + j;
			res = f(res, n, m, r, i);
		}
	}
	assert(res != inf);
	return res;
}

void SolveTest(int test)
{
	int n, m;
	cin >> n >> m;
	cout << fixed << setprecision(14) << f(n, m) << endl;
}

int main()
{
	int T, t;
	T = 1;
	cin >> T;
	FOR(t, 0, T) 
	{
		//cerr << "Solving " << t << "/" << T << endl;
		SolveTest(t);
	}

	return 0;
}