x1 = int(input())
y1 = int(input())
x2 = int(input())
y2 = int(input())

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