#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N=5+1e5;
struct MaxPoly{
    ll a,b;
    MaxPoly(ll _a=0,ll _b=0){a=_a,b=_b; }
};
MaxPoly merge(MaxPoly x,MaxPoly y){
    return MaxPoly(x.a+y.a,max(x.b+y.a,y.b));
}

int main(){
    int T; scanf("%d",&T);
    while(T--){
        int n; ll m; scanf("%d%lld",&n,&m);
        MaxPoly base(0,0);
        ll mx=0,mx2=0;
        for(int i=1;i<=n;++i){
            int x; scanf("%d",&x);
            base=merge(base,MaxPoly(x,0));
            mx=max(mx,merge(MaxPoly(0,0),base).b);
            mx2=max(mx2,base.a);
        }
        if(mx>=m){
            puts("1");
            continue;
        }
        MaxPoly key=merge(MaxPoly(0,0),base);
        m-=key.b;
        if(mx2>=m){
            puts("2");
            continue;
        }
        m-=mx2;
        if(key.a<=0){
            puts("-1");
            continue;
        }
        printf("%lld\n",(m-1)/key.a+3);
    }
    return 0;
}