x1 = int(input());
y1 = int(input());

x2 = int(input());
y2 = int(input());

if((x1 == x2 + 1 or x1 == x2 - 1) and (y1 == y2 + 2 or y1 == y2 - 2)):
    print("YES");
elif((y1 == y2 + 1 or y1 == y2 - 1) and (x1 == x2 + 2 or x1 == x2 - 2)):
    print("YES");
else:
    print("NO");
