import java.io.*; import java.util.*; public class Main{ public static void main(String[] args) throws Exception{ Scanner sc = new Scanner(System.in); while(sc.hasNextInt()){ int month = sc.nextInt(); System.out.println(fun(month)); } } public static int fun(int month){ if (month <= 2) return 1; int[] array = new int[month + 1]; array[1] = array[2] = 1; for (int i = 3; i <= month; i++) { array[i] = array[i - 1] + array[i - 2]; } return array[month]; } }