#include <algorithm>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>

const int MAX_N = 100010;

int T, n;
long long m, a[MAX_N];

int main() {
    std::ios::sync_with_stdio(false);
    std::cin >> T;
    while (T--) {
        std::cin >> n >> m;
        for (int i = 1; i <= n; i++) std::cin >> a[i];
        long long s = 0, max = -1;
        for (int i = 1; i <= n; i++) {
            s = s + a[i];
            s = std::max(s, 0ll);
            max = std::max(max, s);
        }
        long long t = s;
        if (m <= max) {
            std::cout << 1 << std::endl;
            continue;
        }
        if (s == 0) {
            std::cout << -1 << std::endl;
            continue;
        }
        for (int i = 1; i <= n; i++) {
            s = s + a[i];
            s = std::max(s, 0ll);
            max = std::max(max, s);
        }
        if (m <= max) {
            std::cout << 2 << std::endl;
            continue;
        }
        if (s <= t) {
            std::cout << -1 << std::endl;
            continue;
        }
        s = 0, max = -1;
        for (int i = 1; i <= n; i++) {
            s = s + a[i];
            max = std::max(max, s);
        }
        long long rest = m - t - max;
        long long cnt = (rest + s - 1) / s;
        std::cout << cnt + 2 << std::endl;
    }
    return 0;
}