백준 자바 3052 1차원배열(나머지)

https://www.acmicpc.net/problem/3052

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.HashSet;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        HashSet<Integer> h = new HashSet<Integer>();

        for(int i=0; i<10; i++){
            int X = Integer.parseInt(br.readLine());
            h.add(X%42);
        }

        System.out.println(h.size());
    }

}