var
  m : array [1..10000] of char;
  ch : char;
  lk , rk : integer;
  kin : boolean;
  tot ,step: integer;
procedure wrong;
begin
  writeln('NO');
  halt;
end;
begin
  tot := 0;
  repeat
    read(ch);
    inc(tot);
    m[tot] := ch;
  until ch = #26;
  step := 0;
  lk := 0;
  rk := 0;
  while step < tot do begin
    inc(step);
    if (m[step]='(') then begin
      if m[step+1] = '*' then begin
        step := step + 2;
        repeat
          inc(step);
          if step > tot then wrong;
        until (m[step]=')') and (m[step-1]='*');
        continue;
      end else inc(lk);
    end;
    if (m[step]=')') then inc(rk);
    if lk < rk then wrong;
    if (lk > rk) and not (m[step] in ['0'..'9','+','-
','*','/','=','(',')',#10,#13]) then wrong;
  end;
  if lk <> rk then wrong;
  writeln('YES');
end.

I'm having the same problem. Maybe, it's really better to readln and
writeln?