import java.util.*;

public class Main {
    static final int MOD = 1000000007;
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[][] dp = new int[3][n + 4];
        dp[0][1] = 1;
        dp[1][2] = 1;
        dp[2][3] = 1;
        for (int i = 1; i < n; i++) {
            dp[0][i + 1] += dp[1][i] + dp[2][i];
            dp[0][i + 1] %= MOD;
            dp[1][i + 2] += dp[0][i] + dp[2][i];
            dp[1][i + 2] %= MOD;
            dp[2][i + 3] += dp[0][i] + dp[1][i];
            dp[2][i + 3] %= MOD;
        }
        int ans = 0;
        for (int i = 0; i < 3; i++) {
            ans += dp[i][n];
            ans %= MOD;
        }
        System.out.println(ans);
    }
}