#pragma GCC optimize("Ofast","inline","-ffast-math")
#pragma GCC target("avx,sse2,sse3,sse4,mmx")
#include <bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/hash_policy.hpp>
#define int long long
using namespace __gnu_pbds;
using namespace std;

struct custom_hash {
    static uint64_t splitmix64(uint64_t x) {
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }

    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};

int n,m,a[100010];

signed main()
{
    ios::sync_with_stdio(false);
    int t;cin>>t;
    while(t--){
        cin>>n>>m;
        for(int i=1;i<=n;i++) cin>>a[i];
        int x=0,mx=0;
        for(int i=1;i<=n;i++){
            x+=a[i];
            if(x<0) x=0;
            mx=max(mx,x);
        }
        if(mx>=m){
            cout<<1<<'\n';
            continue;
        }
        bool flag=false;
        for(int i=1;i<=n;i++){
            x+=a[i];
            if(x<0) x=0,flag=true;
            mx=max(mx,x);
        }
        if(mx>=m){
            cout<<2<<'\n';
            continue;
        }
        if(flag){
            cout<<-1<<'\n';
            continue;
        }
        int sum=0,maxv=0;
        for(int i=1;i<=n;i++){
            sum+=a[i];
            maxv=max(maxv,sum);
        }
        if(sum==0){
            cout<<-1<<'\n';
            continue; 
        }
        if(x+maxv>=m){
            cout<<3<<'\n';
            continue;
        }
        int a=(m-maxv-x)/sum+((m-maxv-x)%sum!=0);
        cout<<3+a<<'\n';
        continue;
    }
    return 0;
}