import sys

def get_input():
    s = sys.stdin.readline()
    x, y = map(int, s.split())
    return x, y

if __name__ == "__main__":
    w1, w2 = get_input()
    b1, b2 = get_input()
    if ((w1+w2) - (b1+b2)) % 2 == 0:
        print('black')
    else:
        print('white')
    exit(0)