1001*4又3/13+1998/[1998+1998/1999]+4又1/2000=1001*[4+3/13]+1998/[1998（1+1/1999）]+4+1/2000=4*1001+1001*3/13+1999/2000+4+1/2000=4004+4+1001*3/13+1=4009+231=4240