I had a quick guess, is No.1. 2 w! }4 ~9 v& X' ]. N3 z" a: _www1.tvboxnow.comBecause what ever he or she taken, the next person will take what ever had taken with +1 or -1 to ensure they havn't got the same number. at the end, no1 will had the most likely middle number and without a same number. of coz he will need to pick a number from 3 to 19.