#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pi;
typedef pair<ll,ll> pl;
typedef double db;
#define ls(x) ((x)<<1)
#define rs(x) ((x)<<1|1)
#define low(x) ((x)&-(x))
#define all(x) x.begin(),x.end()
#define mp make_pair
#define X first
#define Y second
#ifdef _DEBUG
    const int N=1e3+10;
#else
    const int N=1e6+10;
#endif
const ll mod=1e9+7;
//const ll mod=998244353;
inline ll gcd(ll a,ll b){return !b?a:gcd(b,a%b);}
inline ll q_pow(ll a,ll x){ll ans=1,tmp=a;while(x){if(x&1)(ans*=tmp)%=mod;(tmp*=tmp)%=mod;x>>=1;}return ans;}
template<typename T> inline void re(T &N){int f=1;char c;while((c=getchar())< '0'||c> '9')if(c=='-')f=-1;N=c-'0';while((c=getchar())>='0'&&c<='9')N=N*10+c-'0';N*=f;}
template<class T,class ...T_>inline void re(T&x,T_&...y){re(x),re(y...);}
int n,t=1,st,en;ll m;
int a[N];
ll solve()
{
    ll now=0,ma=0,mi=0,del=0;
    ll ans=1;
    for(int i=1;i<=n;i++)
    {
        now+=a[i];del+=a[i];
        if(now>=m)return ans;
        if(now< 0)now=0;
        mi=min(mi,del);
        ma=max(ma,del);
    }
    ans++;
    for(int i=1;i<=n;i++)
    {
        now+=a[i];
        if(now>=m)return ans;
        if(now< 0)now=0;
    }
    if(del<=0)return -1;
    ll turn=max((m-ma-now+del-1)/del,0ll);
    ans+=turn+1;
    return ans;
}
int main()
{
    #ifdef _DEBUG
        freopen("data.txt","r",stdin);
    #endif
    re(t);
    while(t--)
    {
        re(n,m);
        for(int i=1;i<=n;i++)re(a[i]);
        printf("%lld\n",solve());
    }
}