백준 알고리즘 5597번: 과제 안 내신 분..? - JAVA

 

import java.util.Scanner;
 
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        
        int[] arr = new int[30];
        
        for(int i=0; i<28; i++) {
            int num = sc.nextInt();
            
            arr[num-1] = 1;
        }
        
        for(int i=0; i<arr.length; i++) {
            if(arr[i] != 1) {
                System.out.println(i+1);
            }
        }
    }
}