#include <bits/stdc++.h>

using namespace std;
ifstream fin("text.in");
ofstream fout("text.out");

int litere, cuvinte;
string s;

int main()
{

    while(getline(fin,s))
    {
        for(int i=0; i<s.size(); i++)
            if(isalpha(s[i]) || s[i]=='-')
            {
                cuvinte++;
                while(isalpha(s[i]) || s[i]=='-' && i<s.size())
                {
                    if(isalpha(s[i]))litere++;
                    i++;

                }

                i--;
            }
    }
    fout<<litere/cuvinte;




}