from collections import Counter
import sys


def input(): return sys.stdin.readline().rstrip('\n')


def main():
    n = int(input())
    dp = [1, 1, 2, 2, 3, 4]
    while len(dp) <= n:
        dp.append((dp[-2]+dp[-3]) % 1000000007)

    print(dp[n])


if __name__ == '__main__':
    main()