Score : $300$ points

Problem Statement

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

Constraints

• $2 \leq N \leq 200000$
• $1 \leq A_i \leq 10^9$
• 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.

5
2 6 1 4 5

YES

The elements are pairwise distinct.

6
4 1 3 1 6 2

NO

The second and fourth elements are identical.

2
10000000 10000000

NO