#9530: pascal答案


lsyyw2002 (袁祎炜)


var
  a,b,c:longint;
begin
  while not eof do begin
  readln(a,b);
  if (a=0) or (b=0) then exit;
  while b>0 do begin
    c:=a mod b;
    a:=b;
    b:=c;
  end;
  writeln(a);
end;
end.