#include <bits/stdc++.h>
using namespace std;
int main(){
     ifstream in("text.in");
     ofstream out("text.out");

     int cuv=0,nr=0,i=0,ok=0;
     char s;
     while(in.get(s))
     {
     if(isalpha(s)&&ok==1)
        cuv++;
     if(!isalpha(s))
     ok=1;
     else
     ok=0;

     if((s>='A'&&s<='Z')||(s>='a'&&s<='z'))
          nr++;

     }
     out<<nr/cuv;
}