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

void main(){
    while(true){
        auto line = readln();
        if(line == null){
            break;
        }
        auto strs = line.split();
		if(strs.length < 8){
			break;
		}
		auto input = strs.map!(to!real)();
        auto p1 = input[0] + input[1] * 1.0i, p2 = input[2] + input[3] * 1.0i, p3 = input[4] + input[5] * 1.0i, p = input[6] + input[7] * 1.0i;
        if((dot(p1, p2, p) && dot(p2, p3, p) && dot(p3, p1, p)) || (!dot(p1, p2, p) && !dot(p2, p3, p) && !dot(p3, p1, p))){
            writeln("YES");
        }else{
            writeln("NO");
        }
    } 
}

bool dot(creal base, creal src, creal target){
    real a = (src - base).re, b = (src - base).im, c = (target - base).re, d = (target - base).im;
    return a * d - b * c > 0;
}