import java.util.*;

public class Ex11IsUnique {

	public static boolean isUnique(int[] list) {
		Arrays.sort(list);
		for (int i = 0; i < list.length-1; i++) {
			int n1 = list[i];
			int n2 = list[i+1];
			if (n1 == n2) {
				return false;
			}
		}
		return true;
	}
	
	public static void main(String[] args) {
		int[] list1 = { 1, 2, 3, 4, 5, 6 };
		int[] list2 = { 1, 2, 3, 4, 5, 4, 6 };
		System.out.println( isUnique(list1) );
		System.out.println( isUnique(list2) );
	}

}