#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MAX_N = 1e5+10;
ll t,n,m,a[MAX_N],x,Max;
int main(){
    ios::sync_with_stdio(0);
    cin>>t;
    while(t--){
        cin>>n>>m;
        x = 0;
        Max = 0;
        bool flag = false;
        //cout<<"IN1\n";
        for(int i=1;i<=n;i++){
            cin>>a[i];
            x += a[i];
            if(x<0){
                x = 0;
            }
            if(x>=m){
                flag = true;
            }
        }
        if(flag){
            cout<<"1\n";
            continue;
        }
        ll now = x;
        //cout<<"IN2\n";
        for(int i=1;i<=n;i++){
            now += a[i];
            if(now<0){
                now = 0;
            }
            if(now>x){
                Max = max(Max,now-x);
            }
            if(now>=m){
                flag = true;
            }
        }
        ll temp = now-x;
        if(flag){
            cout<<"2\n";
            continue;
        }
        if(now==x){
            cout<<"-1\n";
            continue;
        }
        ll ans = (m-Max-x)/temp;
        if((m-Max-x)%temp!=0){
            ans+=2;
        }else{
            ans+=1;
        }
        cout<<ans+1<<'\n';
    }
    
    return 0;
}