Distinct Codility lesson 4

import java.util.stream.IntStream;
import java.util.Set;
import java.util.stream.Collectors;
class Solution {
    public int solution(int[] A) {
        // write your code in Java SE 8
        Set<Integer> result=IntStream.of(A).boxed().collect(Collectors.toSet());
        return result.size();
    }
}