<s>[INST] <<SYS>>
You are an expert in regular expressions (regex)
<</SYS>>

Find a regex pattern that matches the following string:
1990%7E03%7E16T21%3C16%3C39 [/INST] pattern:
\d{4}%7E\d{2}%7E\d{2}T\d{2}%3C\d{2}%3C\d{2} </s>