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

int main()
{
  std::ifstream input("text.in");
  std::ofstream output("text.out");
  std::string line;
  bool inside = false;
  unsigned long long int word_counter = 0, char_counter = 0;

  if (!input.is_open()) {
    std::cout << "Sorry, can't open the file.\n";

    if (output.is_open()) {
      output.close();
    }
    return -1;
  }
  else if (!output.is_open()) {
    std::cout << "Sorry, can't open the file.\n";
    input.close();
    return -1;
  }

  while (input.good()) {

    std::getline(input, line);
    for (std::string::iterator it = line.begin(); it != line.end(); ++it) {

      if (!inside && isalpha(*it)) {

	inside = true;
	++word_counter;
      }

      if (inside && !isalpha(*it)) {

	inside = false;
      }

      if (inside) {

	++char_counter;
      }
    }
  }

  output << char_counter / word_counter << std::endl;
  input.close();
  output.close();

  return 0;
}