Day 1
A answers if sees 19-20, pass if sees 0-18
B answers if sees 0-1, 19-20, pass if sees 2-18
Day 2
A answers if sees 0-1, 17-18, pass if sees 2-16
B answers if sees 2-3, 17-18 , pass if sees 4-16
Day 3
A answers if sees 2-3, 15-16, pass if sees 4-14
B answers if sees 4-5, 15-16, pass if sees 6-14
Day 4
A answers if sees 4-5, 13-14, pass if sees 6-12
B answers if sees 6-7, 13-14, pass if sees 8-12
Day 5
A answers if sees 6-7, 11-12, pass if sees 8-10 done here (say 20)