#include <iostream>
#include <fstream>
#include <cstring>

using namespace std;

ifstream fin ("text.in");
ofstream fout ("text.out");
int main(){
    char s[500000];
    int litere=0,cuvinte=0;
    fin.getline(s,500000,'\n');
    for (int i=0;i<strlen(s);i++){
        if ((65<=int(s[i]) and int(s[i])<=90)or(97<=int(s[i]) and int(s[i])<=122)){
            cuvinte++;
            for (;((65<=int(s[i]) and int(s[i])<=90)or(97<=int(s[i]) and int(s[i])<=122)and i<strlen(s));i++)
                litere++;
        }
    }
    if (cuvinte!=0)
        fout <<litere/cuvinte;
    else
        fout <<0;
    return 0;
}