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

using namespace std;

int main()
{ char s[10000], *p;
    int nr=0,  sh=0, k;
    ifstream f("text.in");
    ofstream g("text.out");
    f.get(s,10000);
  k=strlen(s);

    for (int i=0;i<k;i++) {if (isalpha(s[i])) nr++;
                          if(!isalpha(s[i])) s[i]=' ';
                        }

    for (p=strtok(s," ");p;p=strtok(NULL," ")) sh++;

g<<nr/sh;



    return 0;
}