#include <bits/stdc++.h>
using namespace std;

int main(int argc, char **argv) {
    cin.sync_with_stdio(false), cin.tie(nullptr);
    
    int t;
    cin >> t;

    while (t--) {
        int n;
        int64_t m;

        cin >> n >> m;

        vector<int> a(n);

        for (int i = 0; i < n; i++) {
            cin >> a[i];
        }

        int64_t sum = 0;

        for (int i = 0; i < n; i++) {
            sum += a[i];

            if (sum < 0) {
                sum = 0;
            } else if (sum >= m) {
                break;
            }
        }

        if (sum >= m) {
            cout << "1\n";
            continue;
        }

        int64_t round_1 = sum, max_diff = 0, diff = 0;

        for (int i = 0; i < n; i++) {
            sum += a[i];
            diff += a[i];
            max_diff = max(max_diff, diff);

            if (sum < 0) {
                sum = 0;
            } else if (sum >= m) {
                break;
            }
        }

        if (sum >= m) {
            cout << "2\n";
            continue;
        }

        if (sum == round_1) {
            cout << "-1\n";
            continue;
        }

        cout << (m - max_diff - sum - 1) / diff + 4 << "\n";
    }
}