var s:string; i, k1,k2:byte; f:text;
begin assign(f,'text.in'); reset(f);
      assign(f,'text.out'); rewrite(f);
      readln(f,s);
      close(f);
      for i:=1 to length(s) do
      if s[i] in ['A'..'Z','a'..'z'] then inc(k1);
      i:=1;
      while i<=length(s) do begin
       if s[i] in ['A'..'Z','a'..'z'] then begin
        while s[i] in ['A'..'Z','a'..'z'] do inc(i);
        inc(k2);
        end; inc(i);  end;
       writeln(f,'Lungimea medie:',k1 div k2);
       close(f);
      end.