#include <cstdio>
#include <algorithm>
#include <cmath>
#include <map>
#include <cstring>
#include <queue>
#include <vector>
#include <iostream>
#define LL long long
#define LD long double
#define MAXN 1000005
#define MAXM
#define P
#define MP make_pair
#define PB push_back
#define INF 0x3f3f3f3f
#define dbg(a...) fprintf(stderr, a)
using namespace std;

int T, n;
LL m, a[MAXN], pre[MAXN];

LL solve()
{
    scanf("%d%lld", &n, &m);
    LL num=0, maxn=0;
    for(int i=1; i<=n; ++i) {
        scanf("%lld", &a[i]);
        pre[i]=pre[i-1]+a[i];
        maxn=max(maxn, pre[i]);
    }
    for(int i=1; i<=3; ++i) {
        for(int j=1; j<=n; ++j) {
            num=max(num+a[j], (LL)0);
            if(num>=m) return i;
        }
    }
    if(num+maxn>=m) return 4;
    if(pre[n]<=0) return -1;
    m-=num;
    //printf("%d %d\n", m, m-maxn);
    return (m-maxn+pre[n]-1)/pre[n]+4;
}


int main()
{
    scanf("%d", &T);
    while(T--) printf("%lld\n", solve());
    return 0;
}