Given is a sequence of integers A_1, A_2, ..., A_N. If its elements are pairwise distinct, print `YES`; otherwise, print `NO`.

Constraints

* 2 ≤ N ≤ 200000
* 1 ≤ A_i ≤ 10^9
* All values in input are integers.

Input

Input is given from Standard Input in the following format:


N
A_1 ... A_N


Output

If the elements of the sequence are pairwise distinct, print `YES`; otherwise, print `NO`.

Examples

Input

5
2 6 1 4 5


Output

YES


Input

6
4 1 3 1 6 2


Output

NO


Input

2
10000000 10000000


Output

NO
import java.util.*;
public class Main {
    public static void main(String[] args){
    
        Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		HashSet<Integer> a = new HashSet<>();
		int A = 0;
		
		for(int i = 0; i < N; i++) {
			A=sc.nextInt();
			a.add(A);
		}
		
		if(a.size() == N) {
			System.out.println("YES");
		}else {
			System.out.println("NO");
		}
    }
}