f = [[0 for i in range (99)] for j in range (99)]
f[0][0] = 1
for n in range (90):
	for k in range (90):
		f[n + 1][k + 1] += f[n][k]
		f[n + 1][k + 2] += f[n][k]

l, h = [int(i) for i in input().split()]
print (f[l][h])