#region Header
#!/usr/bin/env python3
# from typing import *

import sys
import io
import math
import collections
import decimal
import itertools
from queue import PriorityQueue
import bisect
import heapq

def input():
    return sys.stdin.readline()[:-1]

sys.setrecursionlimit(1000000)
#endregion

# _INPUT = """100
# """
# sys.stdin = io.StringIO(_INPUT)

MOD = 1000000007

def main():
    N = int(input())

    dp = [[0, 0, 0] for _ in range(max(N+1, 5))]
    dp[0][0] = 1
    dp[0][1] = 0
    dp[0][2] = 0
    dp[1][0] = 1
    dp[1][1] = 0
    dp[1][2] = 0
    dp[2][0] = 0
    dp[2][1] = 1
    dp[2][2] = 0
    dp[3][0] = 1
    dp[3][1] = 1
    dp[3][2] = 1
    for i in range(4, N+1):
        dp[i][0] = (dp[i-1][1] + dp[i-1][2]) % MOD
        dp[i][1] = (dp[i-2][0] + dp[i-2][2]) % MOD
        dp[i][2] = (dp[i-3][0] + dp[i-3][1]) % MOD
    print(sum(dp[N]) % MOD)


if __name__ == '__main__':
    main()