#include<bits/stdc++.h>
#define int long long
using namespace std;
const int maxn=1e5+100; 
const int mode=998244353;
int read(){
    int x=0,f=1;char ch=getchar();
    while(!isdigit(ch)){
        if(ch=='-') f=-1;
        ch=getchar();
    }
    while(isdigit(ch)){
        x=x*10+ch-'0';
        ch=getchar();
    }
    return x*f; 
}
int t,n,m,si[maxn],sum[maxn],tot;
signed main(){
    t=read();
    while(t--){
        n=read(); m=read();
        tot=0;
        int maxnum=-4325256464465543;
        bool juge=false;
        for(int i=1;i<=n;++i){
            si[i]=read();
            tot+=si[i];
            maxnum=max(maxnum,tot);
            sum[i]=sum[i-1]+si[i];
            if(sum[i]<0) sum[i]=0; 
            if(sum[i]>=m) juge=true;
        }
        if(juge) cout<<1<<"\n";
        else{
            if(sum[n]<=0){
                cout<<-1<<"\n";
                continue;
            }
            int temp=sum[n];
            bool juge=false;
            bool is=true;
            for(int i=1;i<=n;++i){
                temp+=si[i];
                if(temp>=m){
                    juge=true;
                    break;
                }
                if(temp<=0){
                    is=false;
                    break;
                }
            }
            if(juge){
                cout<<2<<"\n";
                continue;
            }
            if(!is||tot<=0){
                cout<<-1<<"\n";
                continue;
            }
            int ans=(m-sum[n]-maxnum)/tot;
            if(ans*tot+sum[n]+maxnum<m) ans++;
            cout<<ans+2<<"\n";
        }
    }
}