4 : 4 4/5 + 2 2/7 * 5 1/4 - 7 11/12
4*5/1*24+16*21/7*4-7 11/12 5/6 +12-7 11/12 10/12 +12-7 11/12 11 22/12 -7 11/12 4 11/12