#include <stdio.h>
#include <vector>
#include <stdlib.h>
#include <math.h>
#include <algorithm>
#include <map>
#include <queue>
#include <iostream>
#include <set>
#include <cstring>
using namespace std;

const int maxv=101000;
const long long mod=998244353;
const int maxNum=0x7fffffff-10;
const double eps=1e-11;
const double PI=3.1415926535;
typedef long long LL;

LL a[maxv];
inline LL read(){
     LL x=0;
     char ch=getchar();
     while(ch<'0'||ch>'9'){
         ch=getchar();
     }
     while(ch>='0'&&ch<='9'){
         x=(x<<1)+(x<<3)+(ch^48);
         ch=getchar();
     }
     return x;
}
inline void write(LL x)
 {
      if(!x) putchar('0');
     char F[200];
     LL tmp=x>0?x:-x ;
     if(x<0)putchar('-') ;
     int cnt=0 ;
        while(tmp>0)
        {
            F[cnt++]=tmp%10+'0';
            tmp/=10;
        }
        while(cnt>0)putchar(F[--cnt]) ;
    putchar('\n');
}
int main(){
    int t,flag,n;
    LL sum1,sum2,m,minSum,sumAll,sum3;
    scanf("%d",&t);
    while(t--){
        sum1=sum2=sumAll=sum3=flag=0,minSum=maxNum;
        scanf("%d %lld",&n,&m);
        for(int i=1;i<=n;i++) scanf("%lld",&a[i]),sumAll+=a[i];
        for(int i=n;i>=1;i--) sum3+=a[i],minSum=min(sum3,minSum);
        for(int i=1;i<=n;i++){
            sum1+=a[i];
            if(sum1<0) sum1=0;
            if(sum1>=m){write(1);flag=1;break;}
        }
        if(flag) continue;
        sum2=sum1;
        for(int i=1;i<=n;i++){
            sum2+=a[i];
            if(sum2<0) sum2=0;
            if(sum2>=m){write(2);flag=1;break;}
        }
        if(flag) continue;
        if(sum2==sum1){write(-1);continue;}
        if(minSum<0) m+=minSum;
        write(1+(m-sum1+sumAll-1)/sumAll);
    }
    return 0;
}