#include <fstream>
#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;
    bool prevwasword = false;
    for(int i = 0; i < s.size(); i++)
    {
        if(isalpha(s[i]))
        {
            wordsize++;
            prevwasword = true;
        }
        else
        {
            letters += wordsize;
            wordsize = 0;
            if(prevwasword)
            {
                words++;
                prevwasword = false;
            }
        }
    }
    if(prevwasword)
        letters += wordsize;
        words++;

    ki << letters / words;

    ki.close();

    return 0;
}