const litere=['a'..'z','A'..'Z'];
var c:char;
    i,n,k,con,s,med:integer;

begin
  assign(input,'text.in');  reset(input);
  assign(output,'text.out'); rewrite(output);
  while not eof do begin
   read(c);
   if c in litere then inc(con)
                  else begin s:=s+con; if con>0 then inc(k); con:=0; end;
   end;
   write(s div k);
   readln;
   close(input); close(output);
   end.