revert:
	proc options(main);
	dcl
		i fixed,
		sysin file;

	do i = 1 to 10000;
	call p(i,exit);
	exit:
	end;

	p:
		proc(index,lab);
		dcl
			(t, index) fixed,
			lab label;
		on endfile(sysin)
			go to lab;
		put skip list(index,':');
		get list(t);
		if t = index then
			go to lab;
		end p;
	end revert;
