struct P{ll x,y;};

ll sq(ll x) {
	return x*x;
}

ll dist2(P p0,P p1) {
	return sq(p1.x-p0.x)+sq(p1.y-p0.y);
}

bool Ptolemy(ll v0,ll v1,ll v2) {
	return sq(v0+v1-v2)==4*v0*v1;
}

bool IsKyoen(P p0,P p1,P p2,P p3) {
	return Ptolemy(dist2(p0,p1)*dist2(p2,p3),dist2(p0,p2)*dist2(p1,p3),dist2(p0,p3)*dist2(p1,p2));
}

bool IsLinear(P p0,P p1,P p2){
	ll x1=p1.x-p0.x;
	ll y1=p1.y-p0.y;
	ll x2=p2.x-p0.x;
	ll y2=p2.y-p0.y;
	return x1*y2==x2*y1;
}

{
	P p0; rd(p0.x,p0.y);
	P p1; rd(p1.x,p1.y);
	P p2; rd(p2.x,p2.y);
	P p3; rd(p3.x,p3.y);
	wt(!IsLinear(p0,p1,p2)&&IsKyoen(p0,p1,p2,p3)?"YES":"NO");
}