12 times4 X# e* ]" `7 p) A3 `
公仔箱論壇* c3 j% U+ i# o
each time 4 person but 1 need to back to pick up the other 3tvb now,tvbnow,bttvb& w8 X9 f! y% c
return x 10 = 30 people/ o7 E5 d _3 o
1 time return. \8 T9 ?' z0 z& {
2 person on last time # y. @0 T4 t6 `& ctotal : 12 times