#include <iostream>
#include <limits.h>
#include <cmath>
#include <string>
#include <stdio.h>
#include <algorithm>
#include <stdlib.h>
#include <vector>
#include <stack>
#include <map>
#include <fstream>
#include <list>
#include <queue>
#include <iomanip>
#include <deque>
#include <set>

using namespace std;

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

string s;

int main()
{
    int x = 0;
    int cuvinte = 0;
    int litere = 0;

    while(!f.eof())
    {
        f >> s;
        for(int i = 0; i < s.size(); i++)
            if (isalpha(s[i]))
                {
                    x ++;
                    if ( i + 1 == s.size() )
                    {
                        litere += x;
                        cuvinte ++;
                        x = 0;
                    }
                }
            else
            {
                litere += x;
                if (x >= 1)
                    cuvinte ++;

                x = 0;
            }
    }

    g << litere/cuvinte;

    return 0;
}