#include <fstream>
#include <cstring>

using namespace std;

const int NMAX = 1000000;
char propozitie[1 + NMAX];
char sep[] = "!,.;:?- ";

int main()
{
    ifstream in("text.in");
    ofstream out("text.out");
    int sum = 0, nr_cuv = 0;

    in.getline(propozitie, 1 + NMAX);

    char* p = strtok(propozitie, sep);

    while (p)
    {
        nr_cuv++;
        sum += strlen(p);
        p = strtok(NULL, sep);
    }

    out << sum / nr_cuv;

    return 0;
}