BR  Main     ;branch to location Main
sum:	.WORD  0x0000	 ;set up word with zero
num1:	.BLOCK 2	 ;set up a two byte block for num1
num2:	.BLOCK 2	 ;set up a two byte block for num2
num3:	.BLOCK 2	 ;set up a two byte block for num3
Main:	LDA sum,d    ;load zero into the accumulator
	DECI num1,d  ;read and store a decimal number in num1
	ADDA num1,d  ;add the contents of num1 to accumulator
	DECI num2,d  ;read and store a decimal number in num2
	ADDA num2,d  ;add the contents of num2 to accumulator
	DECI num3,d  ;read and store a decimal number in num3
	ADDA num3,d  ;subtract the contents of num3 from accumulator
	STA  sum,d   ;store contents of the accumulator into sum
	DECO sum,d   ;output the contents of sum
	STOP         ;stop the processing
	.END         ;end of the program