#include <fstream>
using namespace std;

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

char sir[1000001];

int main ()
{
    cin.getline(sir , 1000000);

    int lungime = 0 , cuvinte = 0;
    for (int indice_1 = 0 ; sir[indice_1] ; indice_1++)
        if (('a' <= sir[indice_1] && sir[indice_1] <= 'z') || ('A' <= sir[indice_1] && sir[indice_1] <= 'Z'))
        {
            int indice_2 = indice_1;
            while (sir[indice_2 + 1] && (('a' <= sir[indice_2 + 1] && sir[indice_2 + 1] <= 'z') || ('A' <= sir[indice_2 + 1] && sir[indice_2 + 1] <= 'Z')))
                indice_2++;

            lungime += indice_2 - indice_1 + 1 , cuvinte++ , indice_1 = indice_2;
        }

    cout << lungime / cuvinte;
    cout.close(); cin.close();
    return 0;
}