#include <fstream>
#include <ctype.h>
#include <string.h>
using namespace std;
ifstream in("text.in");
ofstream out("text.out");
int main()
{
    string s;
    int litere = 0, i, cuvinte = 0, total_litere = 0;
    in.getline(s, 256);
    for(i = 0; i <= s.length(); i++) {
        if(isalpha(s[i])) litere++;
        else if(litere > 0) {
            total_litere = total_litere + litere;
            cuvinte++;
            litere = 0;
        }
    }
    out << total_litere / cuvinte;
    return 0;
}