Find All Duplicates

Problem statement

A scanner records n badge numbers in the range 1 through n. Each number appears once or twice. Identify every number that appears twice. Return them in increasing order so the audit report is deterministic; print NONE when there are no duplicates.

Input format

First line: n. Second line: n space-separated integers.

Output format

Print duplicate values in increasing order, or NONE.

Constraints

1 <= n <= 100000; 1 <= value <= n; each value appears at most twice.

Sample input

6
1 4 3 4 5 3

Sample output

3 4