import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        long mod = (long)Math.pow(10,9)+7;
        long [][] num = new long [1000001][4];
        num[1][1] = 1;
        num[2][2] = 1;
        num[3][1] = 1;
        num[3][2] = 1;
        num[3][3] = 1;
        for(int i=4; i<=N; i++){
            num[i][1] = num[i-1][2]+num[i-1][3];
            num[i][2] = num[i-2][1]+num[i-2][3];
            num[i][3] = num[i-3][1]+num[i-3][2];
            for(int j=0; j<3; j++){
                num[i][j]%=mod;
            }
        }
        long ans=0;
        for(int i=1; i<=3; i++){
            ans+=num[N][i];
        }
        System.out.println(ans%mod);
    }
}