Permutation Verification

Given an integer N and an array of N integers, determine whether the array is a permutation of the first N natural numbers (i.e., contains every number from 1 to N exactly once). If the array is a permutation, output True; otherwise, output False.

For example, if N = 4 and the array is [4, 3, 1, 2], then the answer is True because it contains all integers from 1 to 4 exactly once. Conversely, if the array has duplicate values or missing elements, the answer is False.

Note: The input will be provided via standard input and the output should be sent to standard output.

inputFormat

The first line contains an integer N which denotes the expected size of the permutation.
The second line contains N space-separated integers representing the elements of the array. If N is 0, the second line may be empty.

outputFormat

Output a single line: True if the array is a permutation of the first N natural numbers, otherwise False.

## sample

4
4 3 1 2

True

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