#include <bits/stdc++.h>

using namespace std;

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

int main()
{
    char ch;
    int len_cuv = 0;
    int nr_cuv = 0;
    int len_total = 0;
    fin.get(ch);
    //fout << ch;
    if(('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z')) ++len_cuv;
    char ant = ch;
    while(!fin.eof())
    {
        fin.get(ch);
        //fout << ch;
        if(('a' <= ch && ch <= 'z') || ('A' <= ch && ch <= 'Z')) ++len_cuv;
        else if(('a' <= ant && ant <= 'z') || ('A' <= ant && ant <= 'Z'))
        {
            len_total += len_cuv;
            len_cuv = 0;
            ++nr_cuv;
        }
        ant = ch;
    }
    //fout << "\n";
    fout << (len_total / nr_cuv) << "\n";
    return 0;
}