100 CALL CLEAR
$MLC F 110 10 3000	; line to include all for compilation 
1000 INPUT "A=":A
1010 INPUT "B=":B
1030 CALL LINK("PGCD",A,B,C)
1040 PRINT "PGCD=";C
1050 END
$PGCD			; here starts the program
	GETPARAM 1 A
	GETPARAM 2 B
	DO
		DIV A B
	WHILE<>
		LET A B
		LET B Z
	LOOP
	PUTPARAM 3 B
$$
$END