#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int n,w[1010],k;
struct node{
    int w,a,b;
} c[1010];

bool cmp(node a,node b){
    if (a.w!=b.w) return a.w<b.w;
    return a.a<b.a;
}

int main(){
    freopen("NPH.in","r",stdin);
    freopen("NPH.out","w",stdout);
    
    int T;
    scanf("%d",&T);
    for (int x=1;x<=T;x++){
        scanf("%d %d",&n,&k);
        bool f=1;
        for (int i=1;i<=n;i++){
            scanf("%d",&w[i]);
            if (w[i]!=1) f=0;
        }
        if (n==1){
            printf("%lld\n",(ll)(w[1]*k));
            continue;
        }
        if (f){
            ll s=1;
            for (ll i=1;;i++){
                //cout<<i<<' '<<s<<'\n';
                s+=s*(ll)n;
                if (s>k){
                    printf("%lld\n",i);
                    break;
                }
            }
            continue;
        }
    }
    
    return 0;
}