7 18 5 24z 3 2 3 1 3 July 8, 2019 16 32 64 128 (7/18+5/24 n) 3 2/3=1/3 (7/18+5/24z) 3 2/3=1/3 (7/18+5/24 y) 3 2/3=1/3