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SUM DC 0
AVE DC 0
IN R1, =KBD
COMP R1, =0
JNEQU loop
JEQU end

loop ADD R3, R1
STORE R3, SUM
ADD R2, =1
IN R1, =KBD
COMP R1, =0
JNEQU loop
JEQU end

end LOAD R1, SUM
DIV R1, R2
STORE R1, AVE
SVC SP, =HALT