import java.util.*;

public class Main {
    static int[][] dp;
    static final int MOD = 1000000007;
	public static void main (String[] args) {
    	Scanner sc = new Scanner(System.in);
    	int n = sc.nextInt();
    	dp = new int[3][n + 5];
    	dp[0][1] = 1;
    	dp[1][2] = 1;
    	dp[2][3] = 1;
    	for (int i = 1; i < n; i++) {
    	    for (int j = 0; j < 3; j++) {
    	        for (int k = 0; k < 3; k++) {
    	            if (j == k) {
    	                continue;
    	            }
    	            dp[k][i + k + 1] += dp[j][i];
    	            dp[k][i + k + 1] %= MOD;
    	        }
    	    }
    	}
    	int ans = 0;
    	for (int i = 0; i < 3; i++) {
    	    ans += dp[i][n];
    	    ans %= MOD;
    	}
    	System.out.println(ans);
    }
}