import std.stdio;
import std.conv;
import std.algorithm;
import std.string;
import std.file;
import std.math;
import std.complex;
 
int main() {
        string l;
        while((l = readln(), l.length)){
                l = l.split("\n")[0];
                
                float x1, y1, x2, y2, x3, y3, xp, yp;
                x1 = to!float(l.split[0]), y1 = to!float(l.split[1]);
                x2 = to!float(l.split[2]), y2 = to!float(l.split[3]);
                x3 = to!float(l.split[4]), y3 = to!float(l.split[5]);
                xp = to!float(l.split[6]), yp = to!float(l.split[7]);
                
                cfloat z1, z2, z3;
                z1 = (x1 - xp) + (y1 - yp) * 1.0i;
                z2 = (x2 - xp) + (y2 - yp) * 1.0i;
                z3 = (x3 - xp) + (y3 - yp) * 1.0i;
                
                cfloat r1, r2, r3;
                r1 = z2 / z1;
                r2 = z3 / z2;
                r3 = z1 / z3;
                
                if(r1.im > 0 && r2.im > 0 && r3.im > 0 || r1.im < 0 && r2.im < 0 && r3.im < 0) write("YES\n");
                else write("NO\n");
                }
        return 0;
        }
 