Codeforces Is your horseshoe on the other hoof?

题目链接：http://codeforces.com/problemset/problem/228/A

import java.util.HashMap;import java.util.Map;import java.util.Scanner;public class Isyourhorseshoeontheotherhoof {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);Map<Integer, Integer> map = new HashMap<>();for(int i = 0; i < 4; i++) {map.put(scanner.nextInt(), 1);}System.out.println(4-map.size());}}