N, M = map(int, input().split())
A = [[0] * M for i in range(N)]
A[0][0] = 1
for i in range(N):
    for j in range(M):
        if j >= 1 and i >= 2:
            A[i][j] += A[i - 2][j - 1]
        if j >= 2 and i >= 1:
            A[i][j] += A[i - 1][j - 2]
print(A[-1][-1])