1.

/**
* Angewandte Mathematik, SS11
* Problem: 11069 - A Graph Problem
* Link: http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=22&page=show_problem&problem=2010
*
* @author Markus Schöllner
* @author Andreas Maier
* @version 1.0, 05/29/2011
*
* Method : Ad-Hoc
* Status : Accepted
* Runtime: 0.224
*/

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


public class Main {

public static void main(String[] args) {

Scanner input = new Scanner(System.in);
int n;
BigInteger bigArray[] = new BigInteger[77];
bigArray[0] = BigInteger.ONE;
bigArray[1] = BigInteger.ONE.add(BigInteger.ONE);
bigArray[2] = BigInteger.ONE.add(BigInteger.ONE);

for ( int c = 3; c < 77; c++ ) {
bigArray[c] = bigArray[c-2].add(bigArray[c-3]);
}
while(input.hasNext()){
n = input.nextInt();
System.out.println(bigArray[n-1]);
}
}
}