#include <iostream>
#include <fstream>
#include <string>

using namespace std;

int main()
{
  ifstream infile;
  ofstream outfile;

  infile.open("text.in");
  outfile.open("text.out");

  string nume;
  int numara_litere = 0, numara_cuvinte = 0;

  for(string cuvant;;)
  {
    infile >> cuvant;
    if(nume == cuvant)
    {
      break;
    }
    else
    {
      for(char l: cuvant)
      {
        if( (l >= 'a') && (l <= 'z') ||
            (l >= 'A') && (l <= 'Z') )
        {
          numara_litere++;
        }
        nume = cuvant;
      }
      numara_cuvinte++;
    }
  }


  outfile << numara_litere / numara_cuvinte;

  infile.close();
  outfile.close();

  return(0);
}