/* File: Fib.java - March 2015 */
package l04;

/**
 * Compute and display the Fibonacci number of the input argument using
 * a somewhat subtle recursive approach.
 *
 * @author Michael Albert
 *
 */
public class Fib{

   public static void main(String[] args) {

      int n = Integer.parseInt(args[0]);
      System.out.println("Fib(" + n + ") = " + fib(n));

   }

   public static long fib(int n) {
   			return fib(0L, 1L, n);
   }
   
   public static long fib(long prev, long curr, int n) {
   		if (n == 0) return curr;
   		return fib(curr, prev+curr, n-1);
   }
}