#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import array

MODULUS = 10 ** 9 + 7


if __name__ == "__main__":
    n = int(input())
    dp = array.array("Q", [1, 2, 2])
    for i in range(3, n):
        dp.append((dp[i - 2] + dp[i - 3]) % MODULUS)
    print(dp[-1])