#include<iostream>
#include<algorithm>
#include<cstring>
#include<vector>
#include<queue>
#include<cmath>
#include<map>

using namespace std;
typedef long long ll;
const int mod=998244353;
const int maxn=1e5+5;
ll a[maxn],sum[maxn],n,m;

namespace IO{
    char buf[1<<20],*P1=buf,*P2=buf;
    //#define gc() getchar()
    #define gc() (P1==P2&&(P2=(P1=buf)+fread(buf,1,1<<20,stdin),P1==P2)?EOF:*P1++)
    #define TT template<class T>inline
    TT void read(T&x)
    {
        x=0;register char c=gc();register bool f=0;
        while(c<48||c>57){f^=c=='-',c=gc();}
        while(47<c&&c<58)x=(x<<3)+(x<<1)+(c^48),c=gc();
        if(f)x=-x;
    }
    inline void write(ll x)
    {
        if(x<0)putchar('-'),x=-x;
        int t[25]={0},cnt=0;
        while(x)t[++cnt]=x%10,x/=10;
        if(!cnt)putchar('0');
        else while(cnt)putchar(t[cnt--]+'0');
        puts("");
    }
};
using namespace IO;

int main()
{
    int t; read(t);
    while(t--)
    {
        read(n); read(m);
        ll x=0,maxv=-1e16;sum[0]=0;
        int flag=0;
        for(int i=1;i<=n;i++)
        {
            read(a[i]),sum[i]=sum[i-1]+a[i]; maxv=max(maxv,sum[i]);
            x+=a[i]; if(x<0)x=0; 
            if(x>=m)flag=1;
        }
        if(flag)write(1);
        else
        {
            ll k=x,mx=-1e16;
            for(int i=1;i<=n;i++)
            {
                x+=a[i]; mx=max(mx,x); if(x<0)x=0;
            }
            ll d=x-k;
            if(mx>=m)
            {
                write(2); continue;
            }
            else if(d<=0)
            {
                write(-1); continue;
            }
            ll ans=(m-maxv-k)%d==0?(m-maxv-k)/d:(m-maxv-k)/d+1;
//            for(int i=1;i<=n;i++)
//            {
//                ll p=m-a[i];
//                ans=min(ans,p%d==0?p/d:p/d+1); 
//            }
//            m-=k;ans++;
//            ans+=(m-maxv)%d==0?(m-maxv)/d:(m-maxv)/d+1;
            write(ans+2);
        }
    }
    return 0;
}