import std.stdio, std.string, std.conv;
import std.array, std.algorithm, std.range;

void main()
{
    foreach(s;stdin.byLine())
    {
        auto m = s.split().map!(to!real).array();
        auto v = [0,1,4,5].map!(i=>m[i]-m[i+2]).array();
        writeln(v[0]*v[2]+v[1]*v[3]?"NO":"YES");
    }
}