#include <iostream>
#include <fstream>
using namespace std;

ifstream in("text.in"); ofstream out("text.out");

int lit=0, cuv=0;
char c;

int isalpha(char c)
{
  if (c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z' ) return 1; return 0;
}

int main()
{

while(!in.eof())
{
  c=in.get();
  if (isalpha(c))
  {
    while(isalpha(c))
    {
      lit++;
      c=in.get();
    }
    cuv++;
  }

}


out<<lit/cuv;



in.close();
out.close();
return 0;
}