#include<iostream>
#include<cassert>

using namespace std;

int t,n,count1,A[1010];

int main()
{
  cin>>t;
  assert( (t<=10)&&(t>=1) );
  int sumn=0;
  
  for(int q=1;q<=t;q++)
  {
    count1=0;
    cin>>n;
    assert(n>=1);
    assert(n<=1000);
    sumn+=n;
    for(int i=0;i<n;i++)
    {
      cin>>A[i];
      assert(A[i]>=-1);
      assert(A[i]<i);
      if(i==0)
	continue;
      if(A[i]==-1)
	count1++;
    }
    double ans1=(double)count1/2;
    cout<<ans1+1<<"\n";
  }
  assert(sumn<=5000);
}