#include <bits/stdc++.h>
using namespace std;
typedef __int128 LL;

LL read() {
    long long x;
    scanf("%lld", &x);
    return x;
}

int n;
LL m, a[100005];

struct node {
    LL ld, lp;
    node() {ld = lp = 0;}
    node(LL d, LL p) {ld = d, lp = p;}
} s;

node merge(node x, node y) {
    node res;
    if (y.ld >= x.lp) {
        res.ld = x.ld + y.ld - x.lp;
        res.lp = y.lp;
    } else {
        res.ld = x.ld;
        res.lp = x.lp + y.lp - y.ld;
    }
    return res;
}

node qpow(node x, LL y) {
    if (y == 0) return (node){0LL, 0LL};
    node t = qpow(x, y >> 1);
    t = merge(t, t);
    if (y & 1) t = merge(x, t);
    return t;
}

int check(LL mid) {
    LL x = qpow(s, mid).lp;
    for (int i = 1; i <= n; i++) {
        x += a[i];
        if (x < 0) x = 0;
        if (x >= m) return true;
    }
    return false;
}

void solve() {
    scanf("%d", &n);
    m = read();
    
    s = (node){0LL, 0LL};
    for (int i = 1; i <= n; i++) {
        a[i] = read();
        if (a[i] > 0) s = merge(s, (node){0LL, a[i]});
        else s = merge(s, (node){-a[i], 0LL});
    }
    if (check(0)) {
        puts("1");
        return ;
    }
    
    LL l = 0, r = 1E18, ans = -2;
    while (l <= r) {
        LL mid = (l + r) / 2;
        if (check(mid)) r = mid - 1, ans = mid;
        else l = mid + 1;
    }
    if (ans > 1E18) ans = -2;
    printf("%lld\n", (long long)ans + 1);
}

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