first ot all ,celebrate to two group which have 6 in a group5 w6 o P) c+ Y
and then celebrate again to 3 in a group from which more heavier* d. k8 {; u4 Q/ y8 |6 F
lastly, take two ping pongs from the heavier group and put in) P. F/ _ h' w* L8 B3 G( h" c
when there are same quality 3 a! `+ s: b. C8 d* n" D3 m
that's mean the third ping pong is different
: r J$ V; d E, c& ~) x7 B
' o0 ^ H. P# ^/ si got it in 1 minute |