题解 | 小红的合数寻找

import java.util.*;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
     public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            int x = in.nextInt();
            ArrayList<Integer> list = new ArrayList<>();
            for (int i = 0; i <= x; i++) {
                list.add(x+i);
            }

            if (list.contains(1)){
                list.remove(1);
            }
            int count = 0;
            for (Integer i : list) {
                for (int j = 2; j < i; j++) {
                    if(i% j == 0){
                        System.out.println(i);
                        count = 1;
                        break;
                    }
                }
                if (count == 1){
                    break;
                }
            }
            if (count == 0){
                System.out.println("-1");
            }
        }
    }
}