#include<bits/stdc++.h>
using namespace std;
long long read(){
    long long tot=0,fh=1;
    char c=getchar();
    while ((c<'0')||(c>'9')){ if (c=='-') fh=-1; c=getchar(); }
    while ((c>='0')&&(c<='9')){ tot=tot*10+c-'0'; c=getchar(); }
    return tot*fh;
}
int T,opt;
long long n,m;
const int maxn=100010;
int i,j,k;
long long a[maxn];
long long tot,thi,ans,mx,mxx;
int main(){
    
    T=read();
    for (opt=1;opt<=T;opt++){
        n=read(); m=read(); tot=0;
        for (i=1;i<=n;i++) a[i]=read();
        for (i=1;i<=n;i++) tot=tot+a[i];
        if (tot<=0){
            thi=0; ans=0;
            for (i=1;i<=n;i++){
                thi=thi+a[i];
                if (thi<0) thi=0;
                if (thi>=m) ans=1;
            }
            if (ans==1){ printf("1\n"); continue; }
            for (i=1;i<=n;i++){
                thi=thi+a[i];
                if (thi<0) thi=0;
                if (thi>=m) ans=2;
            }
            if (ans==2){ printf("2\n"); continue; }    
            printf("-1\n"); continue;
        }
        else{
            thi=0; ans=0;
            for (i=1;i<=n;i++){
                thi=thi+a[i];
                if (thi<0) thi=0;
                if (thi>=m) ans=1;
            }
            if (ans==1){ printf("1\n"); continue; }
            mx=0; mxx=0;
            for (i=1;i<=n;i++){
                mx=mx+a[i];
                mxx=max(mx,mxx);
            }
            if (thi+mxx>=m){ printf("2\n"); continue; }
            ans=((m-thi-mxx-1)/tot)+1+2;
            printf("%lld\n",ans);
        }
    }

    return 0;
}