var x1,y1,x2,y2,r1,r2: integer;
begin
writeln('x1, y1');
readln(x1,y1);
writeln('x2, y2');
readln(x2,y2);
r1:=x1*x1+y1*y1;
r2:=x2*x2+y2*y2;
if r1<r2 then writeln('a')
else writeln('b');
end.
var x1,y1,x2,y2,r1,r2: integer;
begin
writeln('x1, y1');
readln(x1,y1);
writeln('x2, y2');
readln(x2,y2);
r1:=x1*x1+y1*y1;
r2:=x2*x2+y2*y2;
if r1<r2 then writeln('a')
else writeln('b');
end.