#include <bits/stdc++.h>
using namespace std;
#define mp make_pair
#define pb push_back
#define x first
#define y second
typedef pair<int,int> pii;
typedef long long ll;
typedef unsigned long long ull;
template <typename T> void chkmax(T &x,T y){x<y?x=y:T();}
template <typename T> void chkmin(T &x,T y){y<x?x=y:T();}
template <typename T> void readint(T &x)
{
    x=0;int f=1;char c;
    for(c=getchar();!isdigit(c);c=getchar())if(c=='-')f=-1;
    for(;isdigit(c);c=getchar())x=x*10+(c-'0');
    x*=f;
}
/*const int MOD=;
inline int dmy(int x){return x>=MOD?x-MOD:x;}
inline void inc(int &x,int y){x=dmy(x+y);}
int qmi(int x,int y)
{
    int ans=1;
    for(;y;y>>=1,x=1ll*x*x%MOD)
        if(y&1)ans=1ll*ans*x%MOD;
    return ans;
}*/
const int MAXN=100005;

int n,a[MAXN];
ll m;
void solve()
{
    readint(n),readint(m);
    for(int i=1;i<=n;++i)readint(a[i]);
    ll s=0;
    for(int i=1;i<=n;++i)
    {
        s+=a[i];
        chkmax(s,0ll);
        if(s>=m){printf("1\n");return;}
    }
    ll t=s,x=0;
    for(int i=1;i<=n;++i)
    {
        s+=a[i];
        chkmax(s,0ll);
        chkmax(x,s);
        if(s>=m){printf("2\n");return;}
    }
    if(t==s){printf("-1\n");return;}
    printf("%lld\n",(m-x+s-t-1)/(s-t)+2);
}

int main()
{
    #ifdef LOCAL
    freopen("code.in","r",stdin);
//    freopen("code.out","w",stdout);
    #endif
    int T;
    readint(T);
    while(T--)solve();
    return 0;
}