N = int(input())

B = [0] * N

for i in range(N-1):
    u, v = list(map(int, input().split()))
    B[u] += 1
    B[v] += 1

no_b = 0
for i, bi in enumerate(B):
    if bi == 0:
        no_b += 1

print(no_b)

if no_b <= 1:
    print("Bob")
else:
    print("Alice")