#include<bits/stdc++.h>
#define LL long long
#define dl double
#define Pi pair<int,int>
#define SZ(a) ((int)a.size())
using namespace std;

const int N = 1e5 + 10;

int T,n;
LL m;
int a[N];
LL s[5][N];

LL work(){
  LL now = 0;
  for(int o = 1;o <= 4;o++){
    for(int i = 1;i <= n;i++){
      now += a[i];
      if(now < 0)now = 0;
      s[o][i] = now;
      if(now >= m)return o;
    }
  }
  bool flg = 0;
  for(int i = 1;i <= n;i++)if(s[4][i] > s[3][i])flg = 1;
  if(!flg)return -1;
  LL mn = 1e18;
  for(int i = 1;i <= n;i++){
    mn = min(mn,(m - s[4][i] + s[4][i] - s[3][i] - 1) / (s[4][i] - s[3][i]));
  }
  return mn + 4;
}

int main(){
  // freopen("in.txt","r",stdin);
  // freopen("o.txt","w",stdout);
  std::ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
  cin >> T;
  while(T--){
    cin >> n >> m;
    for(int i = 1;i <= n;i++)cin >> a[i];
    cout << work() << endl;
  }
  return 0;
}
/**/