用VC写的扩充的pl0文法编译器

				const a=45,b=27;
				var x,y,g,m :integer;
				procedure swap;
				var temp:integer;
				begin
					temp:=x;
					x:=y;
					y:=temp;
				end
				procedure mod;
					x=x-x/y*y;
				begin
				x:=a;
				y:=b;
				while x 0
				do
				begin
					swap;
					mod;
				end;
				g:=y;
				m:=a*b/g;
				write("x=",x);
				write("g=",g);
				write("m=",m);
				end
				.