/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	static double f (double x, double x0, double x1, double y, double y0, double y1){
		return  (x - x0) * (y1 - y0) - (y - y0) * (x1 - x0);
	}
	public static void main (String[] args) throws java.lang.Exception
	{
		double xa, ya, xb, yb, xc, yc, xd, yd;
		Scanner in = new Scanner(System.in);
		xa = in.nextDouble();
		ya = in.nextDouble();
		xb = in.nextDouble();
		yb = in.nextDouble();
		xc = in.nextDouble();
		yc = in.nextDouble();
		xd = in.nextDouble();
		yd = in.nextDouble();
		double l,m;
		l = f(xc,xb,xa,yc,yb,ya);
		m = f(xd,xb,xa,yd,yb,ya);
		if (l * m < 0) {
			System.out.printf("не выпуклый");
			return;
		}
		double q,w;
		q = f(xa,xc,xb,ya,yc,yb);
		w = f(xd,xc,xb,yd,yc,yb);
		if (q * w < 0) {
			System.out.printf("не выпуклый");
			return;
		}
		double p,r;
		p = f(xa,xd,xc,ya,yd,yc);
		r = f(xb,xd,xc,yb,yd,yc);
		if (p * r < 0) {
			System.out.printf("не выпуклый");
			return;
		}
		double j,k;
		j = f(xb,xa,xd,yb,ya,yd);
		k = f(xc,xa,xd,yc,ya,yd);
		if (j * k < 0) {
			System.out.printf("не выпуклый");
			return;
		}
		System.out.printf(" Выпуклый ");
	}
}