#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
const int N = 1e5 + 50;
ll m, x1, m1, x2, m2;
int t, n, a[N];

ll read() {
    ll x = 0, p = 1;
    char c = getchar();
    for (; !isdigit(c); c = getchar())
        if (c == '-') p = -1;
    for (; isdigit(c); c = getchar())
        x = (x << 3) + (x << 1) + (c & 15);
    return x * p;
}

void write(ll x) {
    if (x >= 10) write(x / 10);
    putchar(x % 10 + '0');
}

void writeln(ll x) {
    write(x);
    putchar('\n');
}

int main() {
    t = read();
    while (t--) {
        n = read();
        m = read();
        for (int i = 1; i <= n; i++)
            a[i] = read();
        x1 = m1 = 0;
        for (int i = 1; i <= n; i++) {
            x1 = max(x1 + a[i], 0LL);
            m1 = max(m1, x1);
            if (x1 >= m) break;
        }
        if (x1 >= m) {
            puts("1");
            continue;
        }
        x2 = m2 = x1;
        for (int i = 1; i <= n; i++) {
            x2 = max(x2 + a[i], 0LL);
            m2 = max(m2, x2);
            if (x2 >= m) break;
        }
        if (x2 >= m) {
            puts("2");
            continue;
        }
        if (x1 < x2) writeln((m - m2 - 1) / (x2 - x1) + 3);
        else puts("-1");
    }
    return 0;
}