import java.util.stream.Stream; import java.util.Scanner; public class Main { public static void main(String[] args) { int n =4; Scanner in = new Scanner(System.in); while(in.hasNext()) { n = in.nextInt(); kStep(n); } } public static void kStep(int n) { Long aLong = Stream.iterate(new long[]{1, 1, 2}, t -> new long[]{t[1], t[2], t[0] + t[2]}) .limit(n).skip(n - 1).findFirst().get()[0]; System.out.println(aLong); } }