#include <fstream>
#include <cstring>
using namespace std;

ifstream cin ("text.in");
ofstream cout ("text.out");

char sir[1500000];

int main ()
{
    int lungime_totala = 0 , numar_cuvinte = 0;
    while (cin >> sir)
    {
        for (int indice = 0 ; sir[indice] ; indice++) {
            if (isalpha(sir[indice]))
            {
                lungime_totala++;
                while (isalpha(sir[indice + 1]))
                    { indice++; lungime_totala++; }

                numar_cuvinte++;
            }
        }
    }

    cout << lungime_totala / numar_cuvinte;
    cout.close(); cin.close();
    return 0;
}