Regex to match either 0-9 digits of any length or exact string N/A

Question

I have a text field which should be entering either 0-9 characters or exact string N/A. I am using this regex: /[\d]|\bN/A\b/ But this is not matching what I want:

What I Want is:

1. 123534 - Match

2. N/A - Match

3. N/AN/A - no match

4. N - no match

5. NA - no match

6. N/A1234 - no match

7. 134234N/A - no match

8. 1234N - no match

My current regex /[\d]|\bN/A\b/ is matching above 6, 7 and 8 case which I don't want.

Answer 1

Here is the regex: ^(\d+|N\/A)$