One day last summer, Tommy decided to take a drive into the countryside. After a few hours' drive he arrived at a farm stand. He tripped getting out of his car and knocked over a huge basket of eggs.

He asked the farmer how many eggs were in the basket because he obviously wanted to compensate her for them. She said she didn't know exactly.

"But I do know,' she said, "that this morning I decided the eggs would be easier to sell if they weren't in a big basket but if they were in little paper bags.

"So when I took all my eggs and placed two in each bag I had one left over. I didn't like that so I took the eggs and I put three in each bag. And when I did that, I also had one left over.
"When I put four in each bag, I had one left over. When I put five in a bag or six in a bag, I had one left over. And when I put seven in a bag, I had none left over."

So here's the question: what's the smallest number of eggs that Tommy should have to pay for?