题解 | 牛牛学数列5

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int a = 0, b = 1;
        for(int i = n/2; i > 0; i--){
            a += b;
            b += a;
        }
        if(n%2 == 0) System.out.println(a);
        else System.out.println(b);

    }
}