#include <bits/stdc++.h>
using namespace std;
#define all(__vv__) (__vv__).begin(), (__vv__).end()
#define endl "\n"
#define pai pair<int, int>
#define ms(__x__,__val__) memset(__x__, __val__, sizeof(__x__))
#define debug(x) cout << #x << ":" << x << '\n'
typedef tuple<int, int> tup;
typedef long long ll; typedef unsigned long long ull; typedef long double ld;
inline ll read() { ll s = 0, w = 1; char ch = getchar(); for (; !isdigit(ch); ch = getchar()) if (ch == '-') w = -1; for (; isdigit(ch); ch = getchar())    s = (s << 1) + (s << 3) + (ch ^ 48); return s * w; }
inline void print(ll x, int op = 10) { if (!x) { putchar('0'); if (op)    putchar(op); return; }    char F[40]; ll tmp = x > 0 ? x : -x;    if (x < 0)putchar('-');    int cnt = 0;    while (tmp > 0) { F[cnt++] = tmp % 10 + '0';        tmp /= 10; }    while (cnt > 0)putchar(F[--cnt]);    if (op)    putchar(op); }
inline ll gcd(ll x, ll y) { return y ? gcd(y, x % y) : x; }
ll qpow(ll a, ll b) { ll ans = 1;    while (b) { if (b & 1)    ans *= a;        b >>= 1;        a *= a; }    return ans; }    ll qpow(ll a, ll b, ll mod) { ll ans = 1; while (b) { if (b & 1)(ans *= a) %= mod; b >>= 1; (a *= a) %= mod; }return ans % mod; }
const int dir[][2] = { {0,1},{1,0},{0,-1},{-1,0},{1,1},{1,-1},{-1,1},{-1,-1} };
const int MOD = 1e9 + 7;
const int INF = 0x3f3f3f3f;
const ll INF64 = 0x3f3f3f3f3f3f3f3f;

const int N = 1e6 + 7;
struct Node {
    ll val;
    int id;
    bool operator < (const Node& opt) const {
        return val < opt.val;
    }
};
ll n, m;
ll p[N];

int solve() {
    n = read(), m = read();
    ll x = 0, max1 = 0;
    for (int i = 1; i <= n; ++i)    p[i] = read();
    for (int i = 1; i <= n; ++i) {
        x = max(x + p[i], 0ll);
        if (x >= m) {
            print(1);
            return 1;
        }
        max1 = max(max1, x);
    }
    if (x == 0) {
        print(-1);
        return 0;
    }
    ll xx = x, max2 = 0;

    for (int i = 1; i <= n; ++i) {
        xx = max(xx + p[i], 0ll);
        if (xx >= m) {
            print(2);
            return 0;
        }
        max2 = max(max2, xx);
    }
    if (max1 == max2 || xx == x) {
        print(-1);
        return 0;
    }

    ll xxx = xx, max3 = 0;

    for (int i = 1; i <= n; ++i) {
        xxx = max(xxx + p[i], 0ll);
        if (xxx >= m) {
            print(3);
            return 0;
        }
        max3 = max(max3, xxx);
    }
    if (max2 == max3 || xxx == xx) {
        print(-1);
        return 0;
    }

    ll deta = max3 - max2;
    ll res = 3 + (m - max3 + deta - 1) / deta;
    print(res);

    return 1;
}

int main() {
    int T = read(); for (int i = 1; i <= T; ++i)
    {
        solve();
        //cout << (solve() ? "YES" : "NO") << endl;
    }
    return 0;
}