#include <bits/stdc++.h>
using namespace std;
 
int main() 
{
	int t,n,i,j,k;
	cin>>t;
	while(t--)
	{
		cin>>n>>k;
		int a[n];
		for(i=0;i<n;i++)
		cin>>a[i];
		int cnt,mn=INT_MAX;
		int sum=0;
		for(i=0;i<1<<n;i++)
		{
		     sum=0;
			 cnt=0;
			 for(j=0;j<n;j++)
			 {
			 	if(i&1<<j)
			 	{sum+=a[j];++cnt;}
			 }
			 if(sum==k)
			 mn=min(mn,cnt);
		}
		if(mn==INT_MAX)
		cout<<"impossible\n";
		else
		cout<<mn<<"\n";
	}
	// your code goes here
	return 0;
}

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Mgo1IDkKMTAgOSA0IDMgNQozIDcKMSAyIDMK

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