#include <algorithm>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>

//#include <atcoder/convolution>
//#include <atcoder/modint> 
//using Modint = atcoder::modint998244353;

using namespace std;
typedef long long ll;

void ex_gcd(ll a, ll b, ll &d, ll &x, ll &y) {
  if (!b) {
    d = a;
    x = 1;
    y = 0;
  } else {
    ex_gcd(b, a % b, d, y, x);
    y -= a / b * x;
  }
}
ll inv(ll a, ll n) {
  ll d, x, y;
  ex_gcd(a, n, d, x, y);
  return d == 1 ? (x % n + n) % (n / d) : -1;
}
ll gcd(ll x, ll y) {
  if (y == 0) return x;
  return gcd(y, x % y);
}

int gcd(int x, int y) {
  if (y == 0) return x;
  return gcd(y, x % y);
}

inline bool scan_d(int &ret) {
   char c; int sgn;
   if(c=getchar(),c==EOF) return 0; //EOF
   while(c!='-'&&(c<'0'||c>'9')) c=getchar();
   sgn=(c=='-')?-1:1;
   ret=(c=='-')?0:(c-'0');
   while(c=getchar(),c>='0'&&c<='9') ret=ret*10+(c-'0');
   ret*=sgn;
   return 1;
}

const int maxn = 100005;
const int mod = 998244353;

int a[maxn];

int main() {
#ifdef suiyuan2009
  freopen("/Users/suiyuan2009/CLionProjects/icpc/input.cpp", "r", stdin);
  freopen("/Users/suiyuan2009/CLionProjects/icpc/output.cpp", "w", stdout);
#endif
  int T;
  cin>>T;
  while(T--){
    int n;
    ll m;
    cin>>n>>m;
    ll sum = 0;
    for(int i=0;i<n;i++){
      scan_d(a[i]);
      sum += a[i];
    }
    bool sign =0;
    ll cur = 0;
    for(int i=0;i<n;i++){
      cur += a[i];
      if(cur<0)cur = 0;
      if(cur>=m){
        sign=1;
        break;
      }
    }
    if(sign){
      cout<<1<<endl;
      continue;
    }
    if(sum<=0){
      // one more time
      for(int i=0;i<n;i++){
        cur += a[i];
        if(cur<0)cur = 0;
        if(cur>=m){
          sign=1;
          break;
        }
      }
      if(sign)cout<<2<<endl;
      else cout<<-1<<endl;
      continue;
    }
    ll l = 0, r = (m-cur+sum-1)/sum - 1, ret=0;
    while(l<=r){
      ll mid = (l+r)>>1;
      ll tmp = cur + sum * mid;
      bool sign = 0;
      for(int i=0;i<n;i++){
        tmp +=a[i];
        if(tmp<0)tmp = 0;
        if(tmp>=m){
          sign=1;
          break;
        }
      }
      if(sign){
        ret = mid;
        r = mid-1;
      } else l = mid + 1;
    }
    cout<<1 + ret + 1<<endl;
  }
  return 0;
}