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