#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
typedef pair<int, int> pii;

const int N = 1e5+10;
const ll INF = 1e18;

ll a[N];
int n;

ll gao(ll cur) {
    ll ans = cur;
    for (int i = 1; i <= n; i++) {
        cur += a[i];
        ans = max(cur, ans);
        cur = max(cur, 0LL);
    }
    return ans;
}

void check(ll cur) {
    for (int i = 1; i <= n; i++) {
        cur += a[i];
        assert(cur >= 0);
    }
}

ll up(ll x, ll y) {
    return (x+y-1)/y;
}

void solve() {
    ll m;
    scanf("%d%lld", &n, &m);

    ll cur = 0;
    ll misum = 0, sum = 0;
    ll ma = -INF;
    bool ans = 0;
    for (int i = 1; i <= n; i++) {
        scanf("%lld", a+i);
        cur += a[i];
        sum += a[i];
        ma = max(ma, sum);
        if (cur >= m) {
    //        printf("1\n");
            ans = 1;
        }
        if (cur < 0) {
            misum += cur;
        }
        cur = max(cur, 0LL);
    }

    if (ans) {
        printf("1\n");
        return ;
    }
    if (gao(cur) >= m) {
        printf("2\n");
        return ;
    }
    if (cur + misum <= 0) {
        printf("-1\n");
        return ;
    }
    check(cur+sum);

    assert(m > cur + ma);
    assert(cur > 0 && ma > 0 && sum > 0);

    ll t = m-ma-cur+sum;
    ll round = up(t, sum);
    // if (cur+sum*(round-1) >= m) round--;

    printf("%lld\n", round+1);
}

int main() {
    int T = 1;
    scanf("%d", &T);
    while (T--) solve();
    return 0;
}