def main():
    N = int(input())
    MOD = 10**9+7
    # ken 2連続まで
    # pa は連続できない
    dp = [0]*3
    dp[1] = 1
    # くばる
    for i in range(1, N):
        pre = [0]*3
        dp, pre = pre, dp
        for j in range(3):
            if j != 2:
                dp[j + 1] += pre[j]
            if j != 0:
                dp[0] += pre[j]
        for j in range(2, -1, -1):
            dp[j] %= MOD

    print(sum(dp)%MOD)

if __name__ == "__main__":
    main()