X, Y, K, P = map(int, input().split())

if Y%2==1:
    if P==1:
        P = -1
    else:
        P = 1

if (K%2==0 and P==1) or (K%2==1 and P==-1):
    c = 1+max(0, Y-K-1)
else:
    c = max(0, Y-K)
    
if c%2==0:
    Q = 1
else:
    Q = -1

if P==Q:
    print('Alice')
else:
    print('Bob')