N = int(input())
dp = [[0] * 3 for i in range(N + 1)]
dp[0][2] = 1
DIV = 10 ** 9 + 7

for i in range(N):
    dp[i + 1][0] += dp[i][2]
    dp[i + 1][1] += dp[i][0]
    dp[i + 1][2] += (dp[i][0] + dp[i][1])
    for c in range(3):
        dp[i + 1][c] %= DIV
        
print(sum(dp[-1]) % DIV)