#include <cstdio>
#include <cstring>
#include <string>
#include <cmath>
#include <iostream>
#include <algorithm>
#include <vector>
#include <stack>
#include <sstream>
#include <map>
#include <set>
#include <queue>
#include <stdlib.h>
typedef long long ll;
using namespace std;
ll a[100005];
int main(){
    int T;
    scanf("%d",&T);
    while(T--){
        ll n,m;
        scanf("%lld %lld",&n,&m);
        ll minn=0,maxn=0,sum=0;//sum记录第一次结果
        ll sum2 = 0; //记录∞最后结果
        for(ll i=1;i<=n;i++){
            scanf("%lld",&a[i]);
            sum = sum + a[i];
            sum2 = sum2 + a[i];
            minn = min(minn,sum2);
            maxn = max(maxn,sum2);
            if(sum < 0) sum = 0;
        }
        ll sum3 = sum2;
        for(ll i=1;i<=n;i++){
//            cout << sum3 << endl;
            sum3 = sum3 + a[i];
            if(sum3 < 0) sum3 = 0;
        }
//        cout << sum << " " << sum2 << " " << sum3 << " " << minn << " " << maxn << endl;
        if(maxn >= m){
            printf("1\n");
            continue;
        }
        if(sum + maxn >= m){
            printf("2\n");
            continue;
        }
        if((sum2 <= 0) || (sum3 <= sum2)){
            printf("-1\n");
            continue;
        }
        ll x = m - sum - maxn;
        if(x % sum2 == 0){
            printf("%lld\n",2+x/sum2);
        }
        else {
            printf("%lld\n",3+x/sum2);
        }
    }
    return 0;
}