#include <bits/stdc++.h>
#define fo(i,a,b) for(int i=a;i<=b;++i)
#define fod(i,a,b) for(int i=a;i>=b;--i)

using namespace std;
typedef long long LL;
typedef pair<int,int> pii;
const int N=100500,INF=1e9+7;
int read(int &n)
{
    bool q=0;n=0;char ch=' ';
    for(;ch!='-'&&(ch<'0'||ch>'9');ch=getchar());
    if(ch=='-')ch=getchar(),q=1;
    for(;ch>='0'&&ch<='9';ch=getchar())n=(n<<3)+(n<<1)+ch-48;
    return q?n=-n:n;
}
unsigned seed = std::chrono::system_clock::now().time_since_epoch().count();
mt19937 rand_num(seed);  // 大随机数
int RD(int q){return rand_num()%q;}


int n,m,ans;
int a[N];
LL K;
LL doit(LL nw)
{
    fo(i,1,n)
    {
        nw=max(0ll,nw+a[i]);
        if(nw>=K)return -i;
    }
    return nw;
}
void init()
{
    scanf("%d%lld",&n,&K);
    fo(i,1,n)read(a[i]);
    LL t=0,mx=0;
    fo(i,1,n)t=t+a[i],mx=max(mx,t);
    t=doit(0);
    if(t<0)return printf("%d\n", 1),void();
    LL t1=doit(t);
    if(t1<0)return printf("%d\n", 2),void();
    if(t==t1)return printf("-1\n"),void();
    LL e=(K-t-mx)/(t1-t);
    LL nw=t+(t1-t)*e;
    LL ans=e+1;
    for(nw=doit(nw);nw>=0;++ans,nw=doit(nw))
    {
        // printf(" %lld\n",nw);
    }
    printf("%lld\n",ans+1);
}
int main()
{
    int q,w,_;
    read(_);
    while(_--)
    {
        init();
    }
    
    return 0;
}