简单

n, m = map(int, input().split())

dp = [[0] * (n + 1) for _ in range(m + 1)]
dp[0][1] = 1

for i in range(1, m + 1):
for j in range(1, n + 1):
left = j - 1
right = j + 1
if left < 1:
left = n
if right > n:
right = 1
dp[i][j] = dp[i-1][left] + dp[i-1][right]

print(dp[m][1])