// #pragma GCC optimize("Ofast,no-stack-protector")
#include <bits/stdc++.h>

using namespace std;

const int N = 2e5 + 10;
const int inf = 1 << 30;
const long long llinf = 1ll << 60;
const double PI = acos(-1);

#define lowbit(x) (x & -x)
typedef long long ll;
typedef double db;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<db, db> pdd;
typedef pair<ll, int> pli;

int n, m, k, q;
int d = 0;
int d1[N], d2[N];
vector<int> E[N];

void dfs(int u, int fa)
{
    d1[u] = d2[u] = 0;
    for (int v : E[u])
    {
        if (v == fa)
            continue;
        dfs(v, u);
        int t = d1[v] + 1;
        if (t > d1[u])
            d2[u] = d1[u], d1[u] = t;
        else if (t > d2[u])
            d2[u] = t;
    }
    d = max(d, d1[u] + d2[u]);
}
void work()
{
    cin >> n;
    for (int i = 1; i < n; i++)
    {
        int x, y;
        cin >> x >> y;
        E[x].push_back(y);
        E[y].push_back(x);
    }
    dfs(1, 0);
    cout << ((d % 2 == 0 || d == 1) ? "Bob\n" : "Alice\n");
}
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int t = 1;
    while (t-- > 0)
    {
        work();
    }
}