4321*1234-4322*12344
=4321*1234-(4321+1)*12344
=4321*1234-4321*12344-12344
=4321*(1234-12344)-12344
=4321*(-11110)-1234
=-(4321*10000+4321*1000+4321*100+4321*10)-12344
=-48006310-12344
=-48018654