#include <fstream>

using namespace std ;

bool isInString(string str) {
    char c ;
    for(int i = 0 ; i < str.size() ; i++) {
        c = str[i] ;
        if((c >= 'A' and c <= 'Z') or (c >= 'a' and c <= 'z')) {
            return 1 ;
        }
    }
    return 0 ;
}

int main() {
    ifstream f("text.in") ;
    string txt ;
    getline(f, txt) ;
    f.close() ;

    int k = 0 ;
    int cuv = 0 ;
    char c ;
    string aux ;
    for(int i = 0 ; i < txt.size() ; i++) {
        c = txt[i] ;
        if((c >= 'A' and c <= 'Z') or (c >= 'a' and c <= 'z')) {
            k++ ;
            aux += c ;
        }
        else {
            if(aux.size() and isInString(aux)) {
                cuv++ ;
            }
            aux = "" ;
        }
    }
    ofstream g("text.out") ;
    g << k / cuv ;
    g.close() ;
    return 0 ;
}