import java.util.Scanner;
public class Main{
	
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
		
		// input
		final int NUM = scan.nextInt();
		long[] kenpa = new long[NUM+1];
		
		// search
		kenpa[1] = 1;
		kenpa[2] = 2;
		kenpa[3] = 2;
		for(int i = 4; i <= NUM; i++){
			kenpa[i] = kenpa[i - 2] + kenpa[i - 3];
		}
		
		// answer
		System.out.println(kenpa[NUM] % 1000000007);
		
		
	}
}