#include <bits/stdc++.h>
#define RAN(v) v.begin(), v.end()
#define pb push_back
#define lb lower_bound
#define ub upper_bound
using namespace std;
typedef long long ll;

template <class T1, class T2>
inline void upd1(T1& a, const T2& b) {
    a = a < b ? a : b;
}

template <class T1, class T2>
inline void upd2(T1& a, const T2& b) {
    a = b < a ? a : b;
}

ll gcd(ll a, ll b) {
    return b ? gcd(b, a % b) : a;
}

struct Ano {
    operator ll() {
        ll x = 0, y = 0, c = getchar();
        while (c < 48) {
            y = c == 45;
            c = getchar();
        }
        while (c > 47) {
            x = x*10 + c-48;
            c = getchar();
        }
        return y ? -x : x;
    }
} buf;

constexpr int N = 1e5 + 5;

int a[N];

int main() {
    int t = buf;
    while (t--) {
        int n = buf;
        ll m = buf;
        for (int i = 0; i < n; ++i) {
            a[i] = buf;
        }
        auto cal = [=] (ll x) -> array<ll, 2> {
            ll s = 0;
            for (int i = 0; i < n; ++i) {
                x = max(x + a[i], 0ll);
                upd2(s, x);
            }
            return {x, s};
        };
        auto x = cal(0);
        if (x[1] >= m) {
            puts("1");
        } else {
            auto y = cal(x[0]);
            if (y[1] >= m) {
                puts("2");
            } else if (x[0] == y[0]) {
                puts("-1");
            } else {
                printf("%lld\n", (m - y[1] - 1) / (y[0] - x[0]) + 3);
            }
        }
    }
}