#include <fstream>
#include <iostream>

#include <string>
#include <ctype.h>

using namespace std;

int main()
{
    ifstream be("text.in");
    ofstream ki("text.out");
    string s;

    getline(be, s);

    int wordsize = 0;
    int letters = 0, words = 0;
    for(int i = 0; i < s.size(); i++)
    {
        if(isalpha(s[i]))
        {
            wordsize++;
        }
        else
        {
           if(wordsize > 0)
           {
               letters += wordsize;
               wordsize = 0;
               words++;
           }
        }
    }
    if(wordsize > 0)
           {
               letters += wordsize;
               wordsize = 0;
               words++;
           }

    if(words != 0)
    ki << letters / words;
    else
    ki << 0;
    ki.close();

    return 0;
}