/* -*- coding: utf-8 -*-
 *
 * 2515.cc:  No.2515 Similar Triangles - yukicoder
 */

#include<cstdio>
#include<algorithm>
 
using namespace std;

/* constant */

/* typedef */

/* global variables */

/* subroutines */

/* main */

int main() {
  int x0, y0, x1, y1, x2, y2 = 0;
  scanf("%d%d%d%d%d", &x0, &y0, &x1, &y1, &x2);

  if (y0 == y1) puts("Yes");
  else puts("No");
  
  return 0;
}