[Silver 1] 1309번 동물원

import java.io.*;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int n = Integer.parseInt(br.readLine());
        int[][] dp = new int[n+1][3];
        dp[1][0] = dp[1][1] = dp[1][2] = 1;
        
        for(int i=2; i<=n; i++) {
            dp[i][0] = (dp[i-1][0]+dp[i-1][1]+dp[i-1][2])%9901;
            dp[i][1] = (dp[i-1][0]+dp[i-1][2])%9901;
            dp[i][2] = (dp[i-1][0]+dp[i-1][1])%9901;
        }
        
        System.out.println((dp[n][0]+dp[n][1]+dp[n][2])%9901);
    }
}