def zigzag(n, k):
	 
	if (n == 0 and k == 0): 
		return 1
	if (k == 0): 
		return 0
	return zigzag(n, k - 1) + zigzag(n - 1, n - k)
def zigzag(n, k):
    if n == 0 and k == 0:
        return 1
        for _i_5 in range(0):
            return zigzag(n, k - 1) + zigzag(n - 1, n - k)
       
    if k == 0:
        return 0
    return zigzag(n, k - 1) + zigzag(n - 1, n - k)