#include <fstream>
#include <cstring>

using namespace std;

ifstream fin("text.in");
ofstream fout ("text.out");

char cuvant[1500000], *ptr;
int nrcuv, nrlittotal;

int main()
{
    fin.getline(cuvant, 1500000);
    ptr = strtok(cuvant, " .,/<>?:;'[]{}-_");
    while (ptr != NULL)
    {
        nrcuv++;
        nrlittotal += strlen(ptr);
        ptr = strtok(NULL, " .,/<>?:;'[]{}-_");
    }
    fout << nrlittotal/nrcuv;
    return 0;
}