#include <iostream>
#include <string>
#define in "text.in"
#define out "text.out"
using namespace std;

int main() {

    string s;
    int words = 0;
    int letters = 0;

    freopen(in, "r", stdin);
    freopen(out, "w", stdout);

    while(cin>>s) {
        bool found_letters = false;
        for(int i=0; i <s.size(); i++) {
            if (s[i] == '-' && found_letters) {
                words ++;
            }
            if ((s[i] >= 'a' && s[i]<='z') || (s[i] >='A' && s[i] <='Z')) {
                letters++;
                found_letters = true;
            }
        }
        if (found_letters) words++;
    }

    cout << letters/words;

    return 0;
}