解;2003又2/1-2002又3/1+2001又2/1-2000又3/1+···+1又2/1-3/1
=2003-2002+2001-2000+...+1-0+(1/2-1/3)*(2003+1)/2
=1+1+1+..+1+1002*1/6
=1002+167
=1169