if READ != 523802 then EXIT; a:= READ;
	NL; OUT(6,0,523803); OUT(6,0,a);
L:	NL; k:= READ; c1:= READ; c2:= READ; t:= READ; d1:= d2:= 0;
	for l:= 1 step 1 until n do
	begin	b:= B[l]; if b= c1 then d1:= l;
		if b= c2 then d2:= l;
		if d1 != 0 & d2 != 0 then l:= n
	end;