from fractions import gcd
from heapq import*
import math
from collections import defaultdict, Counter
import sys
sys.setrecursionlimit(10 ** 7)
MOD = 10 ** 9 + 7


def main():
    n = int(input())
    
    dp = [[0, 0, 0] for i in range(n + 1)]
    dp[0][0] = 1

    for i in range(n):
        dp[i + 1][0] += dp[i][1] + dp[i][2]
        dp[i + 1][1] += dp[i][0]
        dp[i + 1][2] += dp[i][1]
        dp[i + 1][0] %= MOD
        dp[i + 1][1] %= MOD
        dp[i + 1][2] %= MOD

    print((dp[n][0] + dp[n][1] + dp[n][2]) % MOD)


if __name__ == '__main__':
    main()