#include<fstream>
#include<iostream>

using namespace std;

int main(){
    ifstream f("text.in");
    ofstream g("text.out");
    char c;
    long long s = 0, l = 0;
    int nr = 0;
    while (!f.eof()){
        f.get(c);
        if (('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z'))
            l++;
        else{
            if (l > 0){
                nr++;
                s = s + l;
                l = 0;  
            } 
        }
    }
    
    s = s/nr;
    g<<s<<endl;
    return 0;
}