rprogn, 17 bytes

Result

WA

Duration

475ms

Code [DL]

read char p p p p

stdin

04 75 36
65 07 24
29 47 07
98 31 09

stdout

--------------------
MEMORY DUMP
--------------------
--------------------

stderr

/usr/bin/lua5.3: main.lua:1330: ERROR: "main.lua:405: bad argument #1 to 'char' (number expected, got string)" AT WORD 3, 'char'
stack traceback:
	[C]: in function 'error'
	main.lua:1330: in local 'stuff'
	main.lua:1356: in function 'rpn'
	main.lua:1374: in main chunk
	[C]: in ?

strace