uses crt; var a: integer; begin clrscr; write ('ban ung nhap so may tu so 1 tro len: '); readln (a); writeln ('hay nhan so do voi 2'); readln; writeln ('roi cong tiep voi 18'); readln; writeln ('chia tiep cho 2'); readln; writeln ('roi tru di so ma ban dang nghi'); readln; writeln ('ket qua se la 9'); readln; end.