#include<fstream>
#include<cstring>

using namespace std;

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


const int NMAX = (1<<21);

char s[NMAX];char *p;

int number_letters = 0; int number_words = 0;

void Read (){

    fin.getline(s , NMAX, '\0');

}

void get_word(){
    bool ok = 0;

    while(*p && ! ((*p >= 'a' && *p <= 'z')|| (*p >= 'A' && *p <= 'Z'))) ++p;

    while((*p >= 'a' && *p <= 'z')|| (*p >= 'A' && *p <= 'Z')) ++p, ++number_letters, ok = true;

    if(ok) number_words++;
}
int main (){

    Read ();

    p = s;

    while(*p)
        get_word();

    fout << number_letters/number_words;

    return 0;
}