import java.util.*;

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