1def ack(m, n) 2 if m == 0 then 3 n + 1 4 elsif n == 0 then 5 ack(m - 1, 1) 6 else 7 ack(m - 1, ack(m, n - 1)) 8 end 9end 10 11NUM = 9 12ack(3, NUM) 13