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

typedef long long LL;

const int MAXN = 100005;

int n, a[MAXN];
LL m, maxv, sum;

LL calc(LL s) {
    maxv = 0, sum = s;
    for(int i = 1; i <= n; i++) {
        s += a[i];
        sum += a[i];
        maxv = max(maxv, sum);
        if(s < 0) s = 0;
        if(s >= m) return s;
    }
    return s;
}

void solve() {
    scanf("%d%lld", &n, &m);
    for(int i = 1; i <= n; i++) {
        scanf("%d", &a[i]);
    }
    LL s = calc(0);
    if(s >= m) {
        printf("1\n");
        return;
    }
    LL nexts = calc(s);
    // printf("%lld %lld\n", s, nexts);
    if(nexts == s) {
        printf("-1\n");
        return;
    }
    if(nexts >= m) {
        printf("2\n");
        return;
    }
    // printf("%lld\n", maxv);
    LL step = nexts - s;
    s = nexts;
    m -= maxv;
    printf("%lld\n", 2 + (m-1)/step + 1);
}

int main() {
    int T;
    scanf("%d", &T);
    for(int i = 1; i <= T; i++) solve();
    return 0;
}