import java.util.Arrays;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Scanner;
import java.util.Set;

public class Main {
	
	public static final long MOD = 1000000007;
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		
		final int N = sc.nextInt();
		
		long[][] DP = new long[N + 1][3];
		DP[0][0] = 1;
		for(int i = 0; i < N; i++){
			DP[i + 1][0] += DP[i][1];
			DP[i + 1][0] %= MOD;
			DP[i + 1][0] += DP[i][2];
			DP[i + 1][0] %= MOD;
			
			DP[i + 1][1] += DP[i][0];
			DP[i + 1][1] %= MOD;
			
			DP[i + 1][2] += DP[i][1];
			DP[i + 1][2] %= MOD;
		}
		
		//System.out.println(Arrays.deepToString(DP));
		
		long answer = 0;
		for(final long count : DP[N]){
			answer += count;
			answer %= MOD;
		}
		
		System.out.println(answer);
	}

}