## Reverse Engineering challenge #24.

Here is the simplest possible calculator program, simplified version of bc UNIX utility:

123+456
(unsigned) dec: 579 hex: 0x243 bin: 1001000011
120/10
(unsigned) dec: 12 hex: 0xC bin: 1100
-10
(unsigned) dec: 4294967286 hex: 0xFFFFFFF6 bin: 11111111111111111111111111110110
(signed) dec: -10 hex: -0xA bin: -1010
-10+20
(unsigned) dec: 10 hex: 0xA bin: 1010

It is known that it supports 4 arithmetic operations and negative numbers can be denoted with minus before the number.
But it's also known that there are at least 7 undocumented features.
Try to find them all.

More challenges: //challenges.re/; about solutions: //challenges.re/#Solutions.