#!/usr/bin/env python3
#coding:utf-8
from __future__ import unicode_literals
import math
from sys import stdin
# import numpy as np
# from matplotlib import pyplot as plt



def main():
	read=stdin.readline

	#edit here!
	n=int(read())
	m=int(1000000000+7)
	dp=[[0]*3 for i in range(n+1)]


	dp[0][0]=1
	for i in range(n):
		for j in range(3):
			if j==0:
				dp[i+1][1]+=dp[i][0]
				dp[i+1][1]%=m
			elif j==1:
				dp[i+1][2]+=dp[i][1]
				dp[i+1][2]%=m
				dp[i+1][0]+=dp[i][1]
				dp[i+1][0]%=m
			else:
				dp[i+1][0]+=dp[i][j]
				dp[i+1][0]%=m
	
	ans=(dp[n][0]+dp[n][1]+dp[n][2])%m
	print(ans)

if __name__ == '__main__':
    main()