#include<iostream>
#include<algorithm>
using namespace std;

int main()
{
	int testcases = 0;
	int t = 1;
	//	freopen("2487.txt", "r", stdin);
	cin  >>testcases;
	while(testcases)
		 	{
		int sum = 0;
		int need = 0;
		int peonum = 0;
		int sign = 0;
		cin >> need >>peonum;
		int *data;
		data = new int[peonum];
		int i = 0;
		for(i = 0; i < peonum; i++)
		{
			cin >>data[i];
		}
		sort(data, data + peonum);
		
		// 	for(i = peonum - 1; i = 0; i--)
		for(i = peonum - 1; i >= 0; i--)
		{
			sum += data[i];
			if((sum >= need) )
			{
				sign = 1;
				break;
			}
		}
		cout << "Scenario #" << t++ << ":" << endl;
		if(sign == 1)
		{
			/*cout << (peonum - 1) - i << endl;*/
			cout << (peonum - 1) - i +1 << endl;
		}
		else cout << "impossible" <<endl;
		testcases--;
		cout << endl;
		 	}
	return 0;
}