#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

template<class T>
ostream &operator<<(ostream &io, vector<T> a) {
    io << "{";
    for (auto I:a)io << I << " ";
    io << "}";
    return io;
}

template<class T>
ostream &operator<<(ostream &io, set<T> a) {
    io << "{";
    for (auto I:a)io << I << " ";
    io << "}";
    return io;
}

template<class K, class V>
ostream &operator<<(ostream &io, map<K, V> a) {
    io << "(";
    for (auto I:a)io << "{" << I.first << ":" << I.second << "}";
    io << ")";
    return io;
}

void debug_out() {
    cerr << endl;
}

template<typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << ' ' << H;
    debug_out(T...);
}

#ifdef local
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 55
#endif
#define all(x) x.begin(),x.end()

mt19937_64 Rand(123456);

ll Range(ll l, ll r) {
    return l + Rand() % (r - l + 1);
}

const int mod = 998244353;

ll power(ll a, ll b) {
    ll res = 1;
    while (b) {
        if (b & 1)res = res * a % mod;
        a = a * a % mod;
        b >>= 1;
    }
    return res;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
#ifdef local
    freopen("../in.txt", "r", stdin);
#endif
    int _;
    cin >> _;
    while (_--) {
        ll n,m;cin>>n>>m;
        vector<ll> a(n+1);
        for(int i =1;i<=n;i++)cin>>a[i];
        ll x = 0;
        bool ok = 0;
        for(int i =1;i<=n;i++){
            x+=a[i];
            x=max(x,0ll);
            if(x>=m){
                ok = 1;
            }
        }
        if(ok){
            cout<<1<<"\n";continue;
        }
        ll now = x;
        ok = 0;
        bool never = 0;
        ll mx = 0;
        for(int i =1;i<=n;i++){
            x+=a[i];
            if(x<=0){
                never = 1;
            }
            x=max(x,0ll);
            if(x>=m){
                ok = 1;
            }
            mx = max(x,mx);
        }
        if(ok){
            cout<<2<<"\n";continue;
        }
        if(never){
            cout<<-1<<"\n";continue;
        }
        debug(x,now,m);
        cout<<2+(m-mx-1)/(x-now)+1<<'\n';
    }
}