#include<iostream>
using namespace std;
typedef long long ll;
const int N = 2e5 + 10;
ll a[N];
ll st[N];
int main()
{
    int t;
    cin >> t;
    while(t--)
    {
        ll n, m;
        scanf("%lld%lld", &n, &m);
        for (int i = 1; i <= n; i++)
            scanf("%lld", &a[i]);

        ll s = 0, pos = -1,maxv = 0,sum2 = 0;
        bool f = 1;
        for (int i = 1; i <= n; i++)
        {
            sum2 += a[i];
            maxv = max(maxv, sum2);
            s += a[i];
            if (s >= m)
            {
                f = 0;
                break;
            }
            if (s < 0)
            {
                st[i] = s;
                s = 0;
            }
        }
        if(!f)
        {
            cout << 1 << '\n';
            continue;
        }
        if (s <= 0)
        {
            cout << -1 << '\n';
            continue;
        }
        ll sum1 = s;
        for (int i = 1; i <= n; i++)
        {
            sum1 += a[i];
            if (sum1 >= m)
            {
                f = 0;
                break;
            }
            if (sum1 < 0)
            {
                st[i] = sum1;
                sum1 = 0;
            }
        }
        if (sum1 == s)
        {
            cout << -1 << '\n';
            continue;
        }
        if(!f)
        {
            cout << 2 << '\n';
            continue;
        }
        m -= s;
        m -= maxv;
        ll t = sum1 - s;
        cout << 2 + (m + t - 1) / t << '\n';
    }
    return 0;
}