MOD = 10 ** 9 + 7
N = int(input())
tmp = [1, 1, 3]
if N <= 3:
    print(tmp[N - 1])
    exit()

dp = [[0, 0, 0] for _ in range(N + 1)]
dp[1][0] = 1
dp[2][1] = 1
dp[3][0] = 1
dp[3][1] = 1
dp[3][2] = 1
for i in range(4, N + 1):
    for j in range(3):
        dp[i][j] += dp[i - j - 1][(j + 1) % 3]
        dp[i][j] += dp[i - j - 1][(j + 2) % 3]
        dp[i][j] %= MOD
#for i in range(N + 1):
#    print(i, dp[i])
print(sum(dp[N]) % MOD)