#include <iostream>
#include <fstream>
#include <string>

using namespace std;

int trim(string s)
{
    int a = 0, words = 0, total = 0;
    for (int i = 0; i < s.size(); i++)
    {
        if ((s[i] >= 'a' && s[i] <= 'z') || (s[i] >= 'A' && s[i] <= 'Z'))
            a++;
        else
        {
            if (a > 0)
            {
                words++;
                total+= a;
                a = 0;
            }
        }
    }
    return total / words;
}

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

    string line;
    string content;

    while (getline(f, line) != NULL)
        content.append(line);

    g<<trim(content);
    return 0;
}