#include <iostream>
#include <stdio.h>
#include <iomanip>
#include <string>

using std::cout;
using std::cin;
using std::endl;
using std::fixed;
using std::setprecision;

class Sentence{
private:
  char m_line[4000];
  int m_index;
  int m_numOfWords;
  int m_lengthOfWords;

public:
  Sentence():m_index(0),m_numOfWords(1), m_lengthOfWords(0){}

  void insert(char* _word){
    for(int i = 0; _word[i] != '\0'; i++){
      m_line[m_index] = _word[i];

      if(m_line[m_index] >= 'a' && m_line[m_index] <= 'z')
        m_lengthOfWords++;

      if(m_line[m_index-1] == m_line[m_index] && m_line[m_index] == ' ')
        continue;

      if(m_index > 0){
        if(m_line[m_index] == ' '){
          if(m_line[m_index-1] != ' ')
            m_numOfWords++;
        }
      }
      if(m_index > 2){
        if(m_line[m_index-1] == '-')
          if(!(m_line[m_index-2] >= 'a' && m_line[m_index-2] <= 'z') && !(m_line[m_index] >= 'a' && m_line[m_index] <= 'z'))
            m_numOfWords++;
      }

      m_index++;
    }
  }

  void process(){
    cout <<fixed << setprecision(3) << m_lengthOfWords / (float)m_numOfWords << endl;
  }
};

int main(){
  int test = 0;
  int line = 0;
  char str[81]={'\0'};
  char temp[2]={'\0'};

  cin >> test;

  while(test--){
    cin >> line;
    Sentence sen;

    while(line--){
      fflush(stdin);
      cin.getline(str, 80);
      sen.insert(str);      
    }
    sen.process();
  }

  return 0;
}