content: package v103;
  
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.PrintWriter;
  import java.math.BigInteger;
  import java.util.StringTokenizer;
  
  public class Tiling_UVa10359 {
  	
  	static final BigInteger TWO = BigInteger.valueOf(2);
  	static BigInteger[] memo = new BigInteger[260];
  	
  	static BigInteger dp(int n)
  	{
  		if(n == 0)
  			return BigInteger.ONE;
  		if(memo[n] != null)
  			return memo[n];
  		BigInteger op1 = BigInteger.ZERO, op2 = dp(n - 1);
  		if(n > 1)
  			op1 = TWO.multiply(dp(n - 2));
  		return memo[n] = op1.add(op2);
  	}
  	public static void main(String[] args) throws IOException {
  		
  		Scanner sc = new Scanner(System.in);
  		PrintWriter out = new PrintWriter(System.out);
  		while(sc.ready())
  			out.println(dp(sc.nextInt()));
  		out.flush();
  	}
  	
  	static class Scanner 
  	{
  		StringTokenizer st;
  		BufferedReader br;
  
  		public Scanner(InputStream s){	br = new BufferedReader(new InputStreamReader(s));}
  
  		public String next() throws IOException 
  		{
  			while (st == null || !st.hasMoreTokens()) 
  				st = new StringTokenizer(br.readLine());
  			return st.nextToken();
  		}
  
  		public int nextInt() throws IOException {return Integer.parseInt(next());}
  		
  		public long nextLong() throws IOException {return Long.parseLong(next());}
  
  		public String nextLine() throws IOException {return br.readLine();}
  			
  		public boolean ready() throws IOException {return br.ready();}
  
  
  	}
  }
  