n, m = map(int, input().split())
variants = [([None] * m) + [0, 0] for i in range(n)] + [[0] * m
                                                        for i in range(2)]
for i in range(n):
    for j in range(m):
        if i == 0 and j == 0:
            variants[i][j] = 1
        else:
            variants[i][j] = variants[i - 2][j - 1] + variants[i - 1][j - 2]
print(variants[n - 1][m - 1])