If you can count...you can do this!

There is a bus with 7 girls inside,
Each girl has 7 bags,
Inside each bag, there are 7 Big cats,
Each Big cat has 7 small cats,All cats have 4 Legs each!

Question:
How many Legs are there inside the bus?


X-T emailed this math question to me today and it took me a couple of minutes to figure out the answer..now...it's your turn!