第一先判断素数,第二从该整数中间开始向两边遍历

public class Main{
	public static void main(String[] args) {		Scanner sc = new Scanner(System.in);
		while(sc.hasNext()){
			int a = sc.nextInt()/2;
			for(int i=0;i<a;i++){
				if(isS(a-i) && isS(a+i)){
					System.out.println(a-i);
					System.out.println(a+i);
					break;
				}
			}
		}
	}
	public static boolean isS(int a){
		if(a==2 || a==3)return true;
		for(int i=2;i<=a/2;i++){
			if(a%i==0){
				return false;
			}
		}
		return true;
	}
}