Unknown plants grow in my pots

Question

I used the 2 pots to grow tomatoes, but they all died before they flowered. I left the pots by the window (it was closed most of the time). After a couple of weeks, I found some small leaves on the pots and they were kind of even arrayed. I really want to know what am I growing.

Answer 1

How can I send the photo?

Answer 2

If you can send an image we will try to help you make an identification.