#include <fstream>
#include <iostream>
using namespace std;
int main ()
{
    ifstream f("text.in");
    ofstream g("text.out");
    int litera=0,cuvant=0,t=0,m;
    char s;
    while(f.get(s));
    {
                    if (('a'<=s && s<= 'z') || ('A'<=s && s<='Z') )
                    litera ++;
                    else
                    {
                    if(litera)
                    cuvant++;
                    t=t+litera;
                    litera=0;
                    }
                    }
                    m=t/cuvant;
                    g<<m;
                    f.close();
                    g.close();
                    return 0;
                    }