from math import sqrt,sin,cos,tan,ceil,radians,floor,gcd,exp,log,log10,log2,factorial,fsum
from heapq import heapify, heappop, heappush
from bisect import bisect_left, bisect_right
from copy import deepcopy
import copy
import random
from collections import deque,Counter,defaultdict
from itertools import permutations,combinations
from decimal import Decimal,ROUND_HALF_UP
#tmp = Decimal(mid).quantize(Decimal('0'), rounding=ROUND_HALF_UP)
from functools import lru_cache, reduce
#@lru_cache(maxsize=None)
from operator import add,sub,mul,xor,and_,or_,itemgetter
import sys
input = sys.stdin.readline
# .rstrip()
INF = 10**18
mod1 = 10**9+7
mod2 = 998244353

#DecimalならPython
#再帰ならPython!!!!!!!!!!!!!!!!!!!!!!!!!!


'''



'''

N = int(input())
dp = [[0]*3 for _ in range(N+1)]
dp[0][0] = 1

for i in range(1,N+1):
    dp[i][1] += dp[i-1][0]
    dp[i][2] += dp[i-1][1]
    dp[i][0] += dp[i-1][1]+dp[i-1][2]
    
    for j in range(3):
        dp[i][j] %= mod1

print(sum(dp[N])%mod1)