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

#define pb push_back
#define mp make_pair
#define ALL(x) (x).begin(),(x).end()
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
const int maxn = 1e5 + 70;
const int INF = 0x3f3f3f3f;
const ll inf = 0x3f3f3f3f3f3f3f3f;
const int MOD = 1e9 + 7;
const double eps = 1e-7;
const double PI = acos(-1.0);

int n; ll m;

int a[maxn];

ll solve(){
    bool flag = 0;
    ll x = 0, mx = 0;
    for(int i=0;i<n;i++){
        x += a[i];
        if(x < 0){
            x = 0; flag = 1;
        }
        if(x >= m) return 1;
        mx = max(x, mx);
    }

    if(x == 0) return -1;

    if(!flag){
        ll d = m - mx;
        return 1 + 1 + (d-1)/x;
    }

    ll y = x;
    for(int i=0;i<n;i++){
        x += a[i];
        if(x < 0) x = 0;
        if(x >= m) return 2;
        mx = max(x, mx);
    }
    //cout << "y: " << y << " ,x: " << x << " ,mx: " << mx << endl;

    if(x == y) return -1;
    else{
        ll d = m - mx;
        return 2 + 1 + (d-1)/(x-y);
    }
}

int main(){
    //freopen("in.txt", "r", stdin);
    //for(int i=1;i<=31;i++) cout << i << ": " << 10 + 3*(i-1) << endl;
    int T; cin >> T;
    while(T--){
        scanf("%d %lld",&n,&m);
        for(int i=0;i<n;i++) scanf("%d",&a[i]);
        printf("%lld\n", solve());
    }
    return 0;
}