n = int(input())
dp = [[0] * 3 for i in range(max(4, n + 1))]
dp[1][0] = 1; dp[2][1] = 1; dp[3][2] = 1
mod = 10 ** 9 + 7
for i in range(1, n + 1):
    dp[i][0] += dp[i - 1][1] + dp[i - 1][2]
    if i >= 2: dp[i][1] += dp[i - 2][0] + dp[i - 2][2]
    if i >= 3: dp[i][2] += dp[i - 3][0] + dp[i - 3][1]
    dp[i][0] %= mod; dp[i][1] %= mod; dp[i][2] %= mod
print(sum(dp[n]) % mod)