poj2506 Tiling

import java.math.BigInteger;
import java.util.Scanner;


public class Main {


    static BigInteger dp[] = new BigInteger[251];
    static void tile(){
        BigInteger flag = BigInteger.ONE;
        BigInteger three = new BigInteger("3");
        BigInteger two = new BigInteger("2");
        dp[0]=flag;
        dp[1]=flag;
        dp[2]=flag.multiply(three);
        for(int i=3;i<251;i++)
        {
            dp[i]=dp[i-1].add(dp[i-2].multiply(two));
            
        }
        
    }
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        
        while(scan.hasNext()){
            int n=scan.nextInt();
            tile();
            
            System.out.println(dp[n]);
            
        }
        
    }

}