Welcome back to Matika.in!
I recommend creating a password for the login. You will be able to sign in to the web more securely, and you can also sign in to www.geograf.in, where a password is required.
Being here for the first time? In this case, CAUTION! Someone else already uses this login. Sign out and choose another login name.
Have fun with math!
My last solved exercises will be here.