Special Soldier Formation

You are given N soldiers with known heights. Your task is to determine whether it is possible to rearrange the soldiers into a special formation such that every soldier has exactly one taller soldier standing in front of him. In order for such a formation to exist, every soldier must have a unique height. That is, if the heights of the soldiers are given by \(h_1, h_2, \dots, h_N\), then the formation is possible if and only if \(h_i \neq h_j\) for all \(i \neq j\).

Input Format: The first line contains an integer \(N\) representing the number of soldiers. The second line contains \(N\) space-separated integers representing the heights of the soldiers.

Output Format: Output a single line: YES if the formation is possible, or NO otherwise.

inputFormat

The input consists of two lines:

• The first line contains an integer \(N\), the number of soldiers.
• The second line contains \(N\) space-separated integers representing the heights of the soldiers.

outputFormat

Output a single line: YES if it is possible to arrange the soldiers into the special formation; otherwise, output NO.

5
5 4 3 2 1

YES