var f,g:text;
    i,s,nr,t:integer;
    c:char;
begin
  assign(f,'text.in');
  assign(g,'text.out');
  reset(f);
  rewrite(g);
  i:=0;
  s:=0;
  nr:=0;
  while not eoln(f) do
    begin
      read(f,c);
      if (c >='a') and (c <= 'z' ) or (c >='A') and (c <= 'Z') then inc(i)
                            else begin
                                   s:=s+i;
                                   inc(nr);
                                   i:=0;
                                 end;
     end;
  t:=s div nr;
  write(g,t);
  close(f);
  close(g);
end.