X:

X: is an esoteric programming language created by User:A which further minimizes 123.

Instructions

The pointer begins at location 0. The program is executed in a loop, and only terminates if the end of the program is reached. All bits start at the value 0.

Instruction	Description
X	Move left if input is 0. Move right if input is 1.
3	Specifies a jump symbol. If the pointer is below 0, do nothing. If the current bit is 1, skip back to either the previous jump symbol or the start of the program. If the current bit is 0, skip forward to either the next jump symbol or the end of the program.