#include <bits/stdc++.h>
using namespace std;
 
const int N = 1010;
 
long long t,n,w[N],k;
 
int main(){
    freopen("NPH.in","r",stdin);
    freopen("NPH.out","w",stdout);
    scanf("%lld",&t);
    while(t--){
        memset(w,0,sizeof(w));
        scanf("%lld%lld",&n,&k);
        int boo=0;
        for(int i=1;i<=n;i++){   
            scanf("%lld",&w[i]);
            if(w[i]!=1)boo=1;
        }
        if(n==1){
            printf("%lld\n",w[1]*k);
        }else if(boo==0){
            printf("%lld\n",k);
        }
    }
    return 0;
}