def main():
    md = 10 ** 9 + 7
    n = int(input())
    dp = [[0] * 4 for _ in range(n + 1)]
    dp[0][0] = 1
    for i in range(n):
        for j in range(4):
            pre = dp[i][j]
            if pre == 0: continue
            for nj in range(1, 4):
                if nj == j: continue
                if i + nj <= n: dp[i + nj][nj] = (dp[i + nj][nj] + pre) % md
    #p2D(dp)
    print(sum(dp[n])%md)

main()