rprogn, 105 bytes

Result

WA

Duration

476ms

Code [DL]

read "\d" match "v1" =
read "\d" match "v2" =
read "\d" match "v3" =
read "\d" match "v4" =

v1 2 index p

stdin

60 70 91
77 05 05
27 64 40
20 93 28

stdout

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

stderr

/usr/bin/lua5.3: main.lua:1330: ERROR: "main.lua:508: attempt to get length of a nil value (local 'a')" AT WORD 20, 'index'
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