#include <bits/stdc++.h>
#define ll long long
#define mp make_pair
#define fi first
#define se second
#define pb push_back
#define vi vector<int>
#define pi pair<int, int>
#define mod 998244353
template<typename T> bool chkmin(T &a, T b){return (b < a) ? a = b, 1 : 0;}
template<typename T> bool chkmax(T &a, T b){return (b > a) ? a = b, 1 : 0;}
ll ksm(ll a, ll b) {if (b == 0) return 1; ll ns = ksm(a, b >> 1); ns = ns * ns % mod; if (b & 1) ns = ns * a % mod; return ns;}
using namespace std;
int n;
ll m;
const int maxn = 100005;
int a[maxn];
ll s = 0;
int main() {
    int t;
    cin >> t;
    while (t--) {
        cin >> n >> m;
        ll sum = 0;
        for (int i = 1; i <= n; i++) scanf("%d", &a[i]), sum += a[i];
        ll x = 0;
        ll ans = -1;
        ll mx = 0;
        for (int j = 1; j <= 4; j++) {
            if (ans != -1) break;
            for (int i = 1; i <= n; i++) {
                x += a[i];
                chkmax(mx, x);
                if (x >= m) {
                    ans = j;
                    break;
                }
                if (x < 0) x = 0;
            }
        }
        if (sum > 0 && ans == -1) 
            ans = 4 + (m - mx + sum - 1) / sum;
        cout << ans << endl;
    }
    return 0;
}