import java.util.Scanner;


public class Main_yukicoder314 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        final int MOD = 1_000_000_007;

        int n = sc.nextInt();

        int[][] dp = new int[3][n];
        dp[1][0] = 1;

        for (int i = 0; i < n - 1; i++) {
        	for (int j = 0; j < 3; j++) {
        		if (j < 2) {
        			dp[j + 1][i + 1] = (dp[j + 1][i + 1] + dp[j][i]) % MOD;
        		}
        		if (j != 0) {
        			dp[0][i + 1] = (dp[0][i + 1] + dp[j][i]) % MOD;
        		}
        	}
        }

        int ret = 0;
        for (int i = 0; i < 3; i++) {
        	ret += dp[i][n - 1];
        	ret %= MOD;
        }

        System.out.println(ret);

        sc.close();
    }
}