#include <iostream>
#include <fstream>
#include <cstring>

using namespace std;

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

int lenght, wordsN;

int LenghtWord(char cuvant[])
{
    int i = 0;
    while (cuvant[i] != '\0')
    {
        i++;
    }

    return i; 
}

int main()
{   
    char text[1000000];
    in.get(text,999999);
    char *cuvant;
    cuvant = strtok(text," .,-!?");
    while (cuvant != NULL)
    {
        lenght += LenghtWord(cuvant);
        ++wordsN;
        cuvant = strtok(NULL," .,-!?");
    }
    
    out << lenght / wordsN;

    return 0;
}