#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <vector>
using namespace std;

namespace solve
{
    const int maxn = 1e5 + 10;
    
    vector<int> e[maxn];
    inline void add(int x, int y) { e[x].push_back(y), e[y].push_back(x); }

    int n;
    int deg[maxn];

    int col[maxn];
    int mx[maxn];

    int ans = 0;
    void dfs(int x, int fa)
    {
        col[x] = col[fa] ^ 1;
        for (int v : e[x])
            if (v != fa)
                dfs(v, x), mx[x] = max(mx[x], mx[v]);
        if (col[x] == 0)
            mx[x] = max(mx[x], x);
        if (x == n || col[x] == 0)
            return;
        vector<int> a;
        for (int v : e[x])
            if (v != fa)
                a.push_back(mx[v]);
        sort(a.begin(), a.end());
        if (a.size() >= 2)
            ans = max(ans, a[a.size() - 2]);
    }

    void main()
    {
        cin >> n;
        if (n % 2 == 0)
        {
            cout << n << endl;
            return;
        }
        for (int i = 1, x, y; i < n; i++)
            cin >> x >> y, add(x, y), deg[x]++, deg[y]++;
        for (int i = 1; i <= n; i++)
            if (deg[i] == 1)
                ans = max(ans, i);
        dfs(n, 0);
        for (int i = 1; i <= n; i++)
            if (col[i] == 0)
                ans = max(ans, i);
        vector<int> a;
        for (int v : e[n])
            if (mx[v] > 0)
                a.push_back(mx[v]);
        sort(a.begin(), a.end());
        if (a.size() >= 3)
            ans = max(ans, a[a.size() - 3]);
        cout << ans << endl;

    }
}

int main()
{
    ios::sync_with_stdio(false), cin.tie(0);
    int T = 1;
    // cin >> T;
    while (T--)
        solve::main();
}