import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		try (Scanner scan = new Scanner(System.in)) {
			int N = scan.nextInt();
			if(N <= 2) {
				System.out.println(N);
			} else {
				long dp[] = new long[N+1];
				dp[0] = 1;
				dp[1] = 2;
				dp[2] = 2;
				for(int i=3; i<=N; i++) {
					dp[i] = ( dp[i-2] + dp[i-3] ) % (1000000000+7);
				}
				System.out.println(dp[N-1]);
			}
		}
	}
}