I do not expect this will make a material difference to the challenge - presumably you used the quoted commands to generate the answer.
# Automatically figure out what echo options to use so that echo
# '\r\n' actually just outputs the characters CR and LF and nothing
# else. This is very shell dependent.
ECHO_OPTIONS := -e -n -en
ECHO :=
$(foreach o,$(ECHO_OPTIONS),$(if $(call seq,$(shell echo $o '\r\n' | wc -
c),2),$(eval ECHO := echo $o)))
ifeq ($(ECHO),)
$(error Failed to set ECHO, unable to determine correct echo command,
tried options $(ECHO_OPTIONS))
endif