#include <bits/stdc++.h>

using namespace std;

int n, k;

vector<int> v;

int mn;

void rek(int indx, int cnt, int sum)
{
	if (indx == n)
		return;

	if (sum == k && cnt < mn)
		mn = cnt;

	rek(indx + 1, cnt + 1, sum + v[indx]);

	rek(indx + 1, cnt, sum);
}

int main()
{
	int t;
	cin >> t;
	while(t--)
	{
		mn = INT_MAX;
		int x;
		cin >> n >> k;
		for (int i = 0; i < n; i++)
		{
			cin >> x;
			v.push_back(x);
		}
		rek(0, 0, 0);

		if (mn == INT_MAX)
			cout << "impossible\n";
		else
			cout << mn << '\n';

		v.clear();
	}


	return 0;
}