Practice Parsing and State machine with the exercise "MiniCPU Instruction Decoder"

Learning Opportunities

This puzzle can be solved using the following concepts. Practice using these concepts and improve your skills.

Statement

Goal

A simple 8-bit CPU emulator must be debugged. The CPU has 4 registers (R0, R1, R2, R3) initialized to 0.

Instructions are encoded as hexadecimal bytes:

01 X V: MOV - Load value V into register RX
02 X Y: ADD - Add register RY to register RX
03 X Y: SUB - Subtract register RY from register RX
04 X Y: MUL - Multiply register RX by register RY
05 X: INC - Increment register RX by 1
06 X: DEC - Decrement register RX by 1
FF: HLT - Halt execution

Where X and Y are register indices (0-3), and V is an immediate byte value.

All arithmetic wraps at 256 (8-bit unsigned). Overflow wraps to 0, underflow wraps to 255.

The first instruction is not guaranteed to be 01 (MOV). Programs may start with any instruction, including 05 (INC) or 06 (DEC).

The smallest valid program is just FF (HLT).

Execute the program and output the final register values.

Input

Line 1: A string of space-separated hexadecimal bytes program

Output

4 lines: The decimal value of each register R0, R1, R2, R3, one value per line

Constraints

Program length ≤ 100 bytes
For the opcodes 02, 03 and 04, X ≠ Y
Program always ends with HLT (FF) as an opcode. Byte value FF may also appear as an immediate value V.

Example

Input

01 00 0A 01 01 05 02 00 01 03 00 01 FF

Output

Solve it

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