#include <bits/stdc++.h>

using namespace std;

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

string s;
int medie,cate,i,poz,sz,k;
bool ok;

int main()
{
    while(getline(f, s))
    {sz = s.size();
    for(i = 0; i < sz; ++ i)
    {
        if(isalpha(s[i]))
        {
            ++ k;
            ok = 1;
        }
        else
        {
            if(ok)
            {
                medie += k;
                ++ cate;
            }
            ok = 0;
            k = 0;
        }
    }
    if(!cate)
        g << 0;
    else
        g << medie / cate;}
}