a1 = int(input())
a2 = int(input())
b1 = int(input())
b2 = int(input())
if (a1 + a2) % 2 == 0 and (b1 + b2) % 2 == 0:
    print('YES')
elif (a1 + a2) % 2 == 1 and (b1 + b2) % 2 == 1:
    print('NO')
elif (a1 + a2) % 2 == 1 and (b1 + b2) % 2 == 0:
    print('YES')
elif (a1 + a2) % 2 == 0 and (b1 + b2) % 2 == 1:
    print('NO')
