#include <iostream>
#include <fstream>
#include <string>
#include <algorithm>

using namespace std;

ifstream f("text.in");
ofstream g("text.out");

char Text[10000005];
long long Curent, NrCuvinte, Suma;

int main()
{
    f.get(Text, 10000000);


    for (int i=0; i<10000000; i++){
        if (Text[i] >= 'a' && Text[i] <= 'z' || Text[i] >='A' && Text[i] <= 'Z')
            Curent ++;
        else{
            if (Curent > 0)
                NrCuvinte ++;
            Suma += Curent;
            Curent = 0;
        }
    }

    if (Curent > 0)
                NrCuvinte ++;
            Suma += Curent;

    g << Suma/NrCuvinte;

    return 0;
}