#include <bits/stdc++.h>

using namespace std;
main()
{
    int a, b, a1,b1;
   int k = 0;
   cin >> a >> b >> a1 >> b1;
   if (abs(a - a1) + abs(b1 - b)  == 3)
   {
       cout << "YES";
       return(0);
   }
    if (abs(b - b1) + abs(a1 - a)  == 3)
   {
       cout << "YES";
       return(0);
   }
   cout << "NO";

}