import sys
def ackermann (m,n):
    #print "ackermann (", m, "," , n, ")"
    if (m == 0):
	return n+1
    elif ((m > 0) and (n == 0)):
	return ackermann (m-1,1)
    elif ((m > 0) and (n > 0)):
	return ackermann (m-1, ackermann (m, n-1))

print sys.getrecursionlimit ()
#sys.setrecursionlimit (65535)
if (len(sys.argv) > 2):
    print ackermann (int(sys.argv[1]), int(sys.argv[2]))
else:
    print "usage: ackermann m n"