--Untltled(hdu5339) (集合子集的枚举，二进制枚举)

#include<stdio.h>
#include<string.h>
#include<algorithm>
using namespace std;
int  cmp(int a,int b){
	return a > b;
} 
 
int main(){
	
	int t;
	scanf("%d",&t);
	while(t--){
		int ans  = 25;
		int a[10010];
		int n,m;
		scanf("%d%d",&m,&n);
		for(int i = 0;i<m;i++)
		scanf("%d",&a[i]);
		sort(a,a+m,cmp);
		
		for(int i = 0;i<(1<<m);i++){
			int nn = n;
			int ss = 0;
			for(int j = 0;j<m;j++){
				
				if(i & (1<<j)){
					
					nn = nn % a[j];
					ss++;
					
				}
			}
			if(nn == 0){
				
				ans = min(ans,ss);
			}
			
		} 
		
		printf("%d\n",ans==25?-1:ans);
		
	}
	
}