program Geom;

var
   x1, x2, x3, x4, y1, y2, y3, y4: real;

function distance(x1, y1, x2, y2: real): real;
begin
   distance := sqrt(sqr(x2 - x1) + sqrt(y2 - y1));
end;

begin
   readln(x1, y1, x2, y2, x3, y3, x4, y4);
   if (distance(x1, y1, x2, y2) = distance(x3, y3, x4, y4)) and (distance(x1, y1, x3, y3) = distance(x2, y2, x4, y4)) and (distance(x1, y1, x4, y4) = distance(x2, y2, x3, y3))
     then
     writeln('Yes')
   else
     writeln('No');
end.