import java.util.*;
import java.util.stream.*;
class Main {
	public static void main(String[] args){
		System.out.println(numberOfUniqueIntegers(new int[]{1,2,3,4,5,1,5}));
	}
	static int numberOfUniqueIntegers(int[] number) {
	    Map<Integer, Long> freq = Arrays.stream(number).boxed().collect(
	       Collectors.groupingBy(x -> x, Collectors.counting()));
	    return (int) freq.entrySet().stream().filter(e -> e.getValue().equals(1L))
	        .map(Map.Entry::getKey).count();
	}
}