from collections import deque

n = int(input())
 
root = [[] for i in range(n)]
for _ in range(n-1):
    a, b = (int(x) for x in input().split())
    root[b-1].append(a-1)
    root[a-1].append(b-1) 
 
stack=deque([0])
check = [-1]*n
check[0] = 1
 
while len(stack)>0:
    v = stack.popleft()
    for i in root[v]:
        if check[i] == -1:
            check[i]=check[v]+1
            stack.append(i)


count = 0

for i in check:
    if i == -1:
        count += 1
print(count)

if n == 2 or count <= 1:
    print('Bob')
else:
    print('Alice')