#include<iostream>
#include<stdio.h>
using namespace std;
int compare(void const * i,void const * j);
int main()
{
//freopen("acm.acm","r",stdin);
int num;
int i;
int j;
int st;
int sum;
int f_num;
int * a;
cin>>num;
j = ;
while(num --)
{
cin>>st;
cin>>f_num;
sum = ;
a = new int[f_num];
for(i = ; i < f_num; ++ i)
{
cin>>a[i];
}
qsort(a,f_num,sizeof(int),compare);
for(i = ; i < f_num; ++ i)
{
sum += a[i];
if(sum >= st)
{
cout<<"Scenario #"<<j<<":"<<endl;
cout<<i+<<endl;
++j;
cout<<endl;
break;
}
}
if(i == f_num)
{
cout<<"Scenario #"<<j<<":"<<endl;
cout<<"impossible"<<endl;
++ j;
cout<<endl;
}
delete[] a;
}
}
int compare(void const * i,void const * j)
{
return *((int *)j) - *((int *)i);
}