#include<iostream>
#include<queue>
#include<string.h>
#include<algorithm>
#include<string>
#include<iomanip>
#include<vector>
#include<set>
#include<cmath>
#include<map>
#include<list>
#include<stack>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define int long long
const int maxn = 1e5 + 7;
const int INF = (1ll << 63) - 1;
const int mod = 998244353;
int arr[maxn], pre[maxn], c[maxn];
void work() {
    int n, m; cin >> n >> m;
    ll sum = 0;
    for (int i = 1; i <= n; ++i) { cin >> arr[i]; sum += arr[i]; pre[i] = arr[i]; }
    for (int i = 1; i <= n; ++i) {
        pre[i] += pre[i - 1];
        if (pre[i] < 0)pre[i] = 0;
        if (pre[i] >= m) {
            cout << 1 << '\n'; return;
        }
    }
    for (int i = 1; i <= n; ++i) {
        c[i] = arr[i];
        c[i] += c[i - 1];
    }
    ll x = pre[n];
    for (int i = 1; i <= n; ++i) { x += arr[i]; if (x < 0)x = 0; if (x >= m) { cout << 2 << '\n'; return; } }
    if (x == pre[n]) {
        cout << -1 << '\n'; return;
    }
    ll mn = INF;
    for (int i = 1; i <= n; ++i) {
        mn = min(mn, m - x - c[i]);
    }
    ll cnt = 2;
    ll d = mn / sum; cnt += d;
    if (d * sum + x >= m) {
        cout << cnt << '\n'; return;
    }
    ll sum1 = d * sum + x;
    for (int k = 1;; ++k) {
        for (int i = 1; i <= n; ++i) {
            sum1 += arr[i];
            if (sum1 >= m) {
                cout << cnt + k << '\n'; return;
            }
        }
    }
}
signed main() {
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int T; cin >> T;
    for (int i = 1; i <= T; ++i) {
        //        cout << "Case #" << i << ": ";
        work();
    }
}