#agc017d. [agc017_d]Game on Tree

[agc017_d]Game on Tree

Problem Statement

There is a tree with NN vertices numbered 1,2,...,N1, 2, ..., N. The edges of the tree are denoted by (xi,yi)(x_i, y_i).

On this tree, Alice and Bob play a game against each other. Starting from Alice, they alternately perform the following operation:

  • Select an existing edge and remove it from the tree, disconnecting it into two separate connected components. Then, remove the component that does not contain Vertex 11.

A player loses the game when he/she is unable to perform the operation. Determine the winner of the game assuming that both players play optimally.

Constraints

  • 2leqNleq1000002 \\leq N \\leq 100000
  • 1leqxi,yileqN1 \\leq x_i, y_i \\leq N
  • The given graph is a tree.

Input

Input is given from Standard Input in the following format:

NN x1x_1 y1y_1 x2x_2 y2y_2 : xN1x_{N-1} yN1y_{N-1}

Output

Print Alice if Alice wins; print Bob if Bob wins.


Sample Input 1

5
1 2
2 3
2 4
4 5

Sample Output 1

Alice

If Alice first removes the edge connecting Vertices 11 and 22, the tree becomes a single vertex tree containing only Vertex 11. Since there is no edge anymore, Bob cannot perform the operation and Alice wins.


Sample Input 2

5
1 2
2 3
1 4
4 5

Sample Output 2

Bob

Sample Input 3

6
1 2
2 4
5 1
6 3
3 2

Sample Output 3

Alice

Sample Input 4

7
1 2
3 7
4 6
2 3
2 4
1 5

Sample Output 4

Bob