#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define _for(i,a,b) for(register int (i)=(a);(i)<=(b);(i)++)
#define For(i,a,b) for(register int (i)=(a);(i)>=(b);(i)--)
#define INF 0x7fffffff
#define il inline
#define rg register
int T;
int n;
ll m;
int a[100005];
ll sum,x,qwq;
void solve(){
    sum=0,qwq=0,x=0;
    scanf("%d%lld",&n,&m);
    _for(i,1,n) scanf("%d",&a[i]), sum+=a[i], qwq=max(qwq,sum);
    _for(i,1,n){
        x+=a[i];
        if(x<0) x=0;
        if(x>=m){
            puts("1");
            return;
        }
    }
    if(x==0) return puts("-1"), void();
    _for(i,1,n){
        x+=a[i];
        if(x<0) return puts("-1"), void();
        if(x>=m) return puts("2"), void();
    }
    if(sum==0) return puts("-1"), void();
    ll ans;
    if((m-x-qwq)%sum==0) ans=(m-x-qwq)/sum+3;
    else ans=(m-x-qwq)/sum+4;
    printf("%lld\n",ans);
}
int main(){
    scanf("%d",&T);
    while(T--) solve();
    return 0;
}