#include <bits/stdc++.h>
#define ll long long
#define N 100005
using namespace std;
int T;
int n;
ll m, a[N], ans, x, x2, maxx;
ll solve() {
    scanf("%d%lld", &n, &m);
    for (int i = 1; i <= n; ++i) {
        scanf("%lld", &a[i]);
    }
    x = 0;
    for (int i = 1; i <= n; ++i) {
        x += a[i];
        if (x < 0) x = 0;
        if (x >= m) return 1;
    }
    x2 = x;
    maxx = x;
    for (int i = 1; i <= n; ++i) {
        x2 += a[i];
        if (x2 < 0) x2 = 0;
        maxx = max(maxx, x2);
        if (x2 >= m) return 2;
    }
    if (x2 == x) return -1;
    ans = (m - maxx) / (x2 - x) * 1ll + 1ll;
    x2 += (ans - 3) * (x2 - x);
    //printf("x=%lld x2=%lld maxx=%lld ans=%lld\n", x, x2, maxx, ans);
    for (int i = 1; i <= n; ++i) {
        x2 += a[i];
        if (x2 < 0) x2 = 0;
        if (x2 >= m) {
            //printf("hello1\n");
            return ans;
        }
    }
    //printf("ans=%lld x2=%lld", ans, x2);
    ++ans;
    for (int i = 1; i <= n; ++i) {
        x2 += a[i];
        if (x2 < 0) x2 = 0;
        if (x2 >= m) {
            //printf("hello2\n");
            return ans;
        }
    }
    //printf("ans=%lld x2=%lld", ans, x2);
    ++ans;
    for (int i = 1; i <= n; ++i) {
        x2 += a[i];
        if (x2 < 0) x2 = 0;
        if (x2 >= m) {
            //printf("hello3\n");
            return ans;
        }
    }
    //printf("ans=%lld x2=%lld", ans, x2);
    ++ans;
    for (int i = 1; i <= n; ++i) {
        x2 += a[i];
        if (x2 < 0) x2 = 0;
        if (x2 >= m) {
            //printf("hello4\n");
            return ans;
        }
    }
    //printf("ans=%lld x2=%lld", ans, x2);
    return ans;
}
int main() {
    scanf("%d", &T);
    while (T--) {
        printf("%lld\n", solve());
    }
}