I have a string which has this pattern “@@@” 0 or more times in it. I want a regex which is valid only if this pattern occurs exactly 2 times in the string.
Here some examples :

• @@@ereruie@@@rherh is valid.
• frfr;:060@fjfir@@@fjuh254@@@ is valid.
• frf@@frfe@@@frehfueh is not valid.
• @@@fhreuihfeurf@@@hfurehfu@@@fr is not valid.

How can I write that ?
^(?:[^@]*@@@[^@]*){2}[^@{3,}]$ is what I tried but it doesn’t work.