#include<bits/stdc++.h>

typedef long long ll;
typedef std::pair<ll, ll> pii;
const int N = 1e6 + 10;
const int inf = 0x3f3f3f3f;
const int mod = 1e9 + 7;
const double eps = 1e-9;

ll a[N], sum[N];

int main()
{
    std::ios::sync_with_stdio(0);
    std::cin.tie(0);
#ifdef ONLINE_JUDGE
#else
    freopen("in.txt","r",stdin);
    freopen("out.txt","w",stdout);
#endif
    int t;
    std::cin >> t;
    while(t--)
    {
        ll n, k;
        std::cin >> n >> k;
        for(int i = 1; i <= n; i ++)
        {
            std::cin >> a[i];
            a[i + n] = a[i];
        }
        bool f = false;
        ll cnt = 0;
        ll max = 0;
        for(int i = 1; i <= n * 2; i++)
        {
            sum[i] = a[i] + sum[i - 1];
            if(i <= n) max = std::max(max, sum[i]);
            cnt += a[i];
            if(cnt < 0) cnt = 0;
            if(cnt >= k)
            {
                if(i > n)
                {
                    std::cout << 2 << std::endl;
                }
                else std::cout << 1 << std::endl;
                f = true;
            }
            if(f) break;
        }
        if(f) continue;
        if(sum[n] <= 0)
        {
            std::cout << -1 << std::endl;
            continue;
        }
        ll x = 0;
        for(int i = 1; i <= n; i++)
        {
            x += a[i];
            if(x < 0) x = 0;
        }
        //std::cout << x << ' ' << sum[n] << std::endl;
        k -= x;
        k -= max;
        //std::cout << k << std::endl;
        if(k <= 0)
        {
            std::cout << 2 << std::endl;
            continue;
        }
        k = (k + sum[n] - 1) / sum[n] + 2;
        std::cout << k << std::endl;
    }
}