MOD = 10 ** 9 + 7

n = int(input())
dp = [[0 for _ in range(4)] for _ in range(n + 1)]
dp[0][0] = 1
for i in range(n):
  for j in range(4):
    for k in range(1, 4):
      if j != k and i + k <= n:
        dp[i + k][k] = (dp[i + k][k] + dp[i][j]) % MOD

print(sum(dp[-1]) % MOD)