Task16Lab4_2

import java.util.Scanner;

class Task17_4 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int i = 2, f1 = 0, f2 = 1, cur = 0;
        int n = sc.nextInt();
        while (i <= n) {
            cur = f1 + f2;
            f1 = f2;
            f2 = cur;
            i++;
        }
        if (n <= 1)
            System.out.println(n);
        else System.out.println(cur);
    }
}