#include"fstream.h"
#include"string.h"
int main()
{
 char l[2];
 int lit=0,cuv=0,med=0,aux=0;
 ifstream in("text.in");
 ofstream out("text.out");
 while(!in.eof())
 {
  in.get(l,2);
  if((strcmp(l,"a")>=0 && strcmp(l,"z")<=0) || (strcmp(l,"A")>=0 && strcmp(l,"Z")<=0))
  {
   lit++;
  }
  else
   if(lit)
   {
    cuv++;
    aux+=lit;
    lit=0;
   }
   else
    lit=0;
 }
 med=aux/cuv;
 out<<med;
 in.close();
 out.close();
 return 0;
}