#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;
}