i know!
. i& G) h3 d9 G6 L y/ ~* l8 ctvb now,tvbnow,bttvbwhen they can have 15 mins discussion.5.39.217.76( z$ D* H" v4 m" K+ S+ i" A X- j
make 1 of them to do a specific job whcih is counting
/ k, O2 o1 T# ?) `only him can turn on off off the light.
; D8 [8 Q/ g# u% uBasically, if you are the first time to get in the room, turn on the light,
2 X! L7 @) [$ m, I4 l) p0 dtvb now,tvbnow,bttvbthen wait for "the special man" to turn the light off....5.39.217.76* f) Y# \; e3 B L/ k
when "the special man" count in up to 30 (included himself)
* B+ t2 A8 J( M+ \0 E; T5 kthen it is done! |