#include<bits/stdc++.h>
#define db double
#define reg register
#define LL long long
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define ull unsigned long long
#define rep(i,a,b) for(int i=a,i##end=b;i<=i##end;++i)
#define drep(i,a,b) for(int i=a,i##end=b;i>=i##end;--i)
#define erep(i,a) for(int i=head[a];i;i=e[i].nxt)


using namespace std;
bool Handsome;
inline LL rd(){
    reg LL x=0;reg char o=getchar();reg bool O=0;
    for(;o<48 || 57<o;o=getchar())if(o=='-')O=1;
    for(;48<=o && o<=57;o=getchar())x=(x<<1)+(x<<3)+(o^48);
    return O?-x:x;
}
inline void Mi(LL &x,LL y){if(x>y && (x=y));}
inline void Mx(LL &x,LL y){if(x<y && (x=y));}
const int M=1e5+5;
int n,p;LL m,a[M],tot,mi[M],mx[M];
void Clear(){
    tot=0;p=1;
    memset(mx,0,sizeof(mx));
}
void solve(){
    n=rd();m=rd();
    rep(i,1,n)a[i]=rd();
    LL t=0;
    rep(i,1,n){
        t+=a[i];Mx(mx[p],t);
        if(t<0)mi[p++]=t,tot+=t,t=0;
        if(t>=m)return puts("1"),void();
    }
    LL c=t;mi[p]=0;
    rep(i,1,p){
        if(c+mx[i]>=m)return puts("2"),void();
        c+=mi[i];
        if(c<=0)return puts("-1"),void();
    }
    LL s=m;c=0;
    rep(i,1,p){
        Mi(s,m-mx[i]-c);
        c+=mi[i];
    }
    LL d=t+tot;
    LL ans=(s-t-1)/d+3;
    printf("%lld\n",ans);
}
bool Most;
int main(){
//    printf("%.2lfMB\n",(&Most-&Handsome)/1024.0/1024.0);
    int t=rd();
    while(t--)Clear(),solve();
    return 0;
}