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

typedef long long s64;
const int D=998244353;
s64 pow_mod(s64 x,int y){
    s64 ans=1;
    while(y){
        if(y&1)ans=ans*x%D;
        x=x*x%D;y>>=1;
    }
    return ans;
}
const int N=1e5+5;
int a[N];
s64 sum[N],mx[N],mn[N];

int main(){
#ifdef kcz
    freopen("1.in","r",stdin);//freopen("1.out","w",stdout);
#endif
    int tt;
    cin>>tt;
    while(tt--){
        int n;s64 m;
        cin>>n>>m;
        for(int i=1;i<=n;++i){
            scanf("%d",a+i);
            sum[i]=sum[i-1]+a[i];
            mn[i]=min(mn[i-1],sum[i]);
            mx[i]=max(mx[i-1],sum[i]);
        }
        s64 x=0;
        for(int i=1;i<=n;++i){
            x=max(0LL,x+a[i]);
            if(x>=m)break;
        }
        if(x>=m){
            puts("1");
            continue;
        }
        for(int i=1;i<=n;++i){
            x=max(0LL,x+a[i]);
            if(x>=m)break;
        }
        if(x>=m){
            puts("2");
            continue;
        }
        if(sum[n]<=0){
            puts("-1");
            continue;
        }
        //x+(k-3)*sum[n]+mx[n]
        cout<<(m-mx[n]-x+sum[n]*4-1)/sum[n]<<endl;
    }
}