#include <bits/stdc++.h>
using namespace std;
#define int long long
const int mxn = 100005;
vector<vector<int>>adj(mxn);
vector<int>good(mxn);
void dfs(int u, int p){
    for(int nxt: adj[u]){
        if(nxt==p)continue;
        dfs(nxt,u);
        if(good[nxt])good[u] = 1;
    }
}
void reset(int n){
    for(int i = 1; i<=n; i++){
        good[i] = 0;
    }
}
signed main(){
    cin.tie(nullptr)->sync_with_stdio(false);
    int n;
    cin >> n;
    for(int i = 1; i<n; i++){
        int x,y;
        cin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    vector<int>dis(n+1);
    vector<bool>vis(n+1);
    queue<int>q;
    q.push(1);
    vis[1] = true;
    while(q.size()){
        int cur = q.front(); q.pop();
        for(int nxt: adj[cur]){
            if(vis[nxt])continue;
            dis[nxt] = dis[cur]^1;
            vis[nxt] = true;
            q.push(nxt);
        }
    }
    if(n%2==0){
        cout << n << '\n';
        return 0;
    }
    int low = 0; int high = n+1;
    while(low + 1 < high){
        int mid = (low+high)/2;
        set<int>s;
        for(int i = mid; i<=n; i++){
            s.insert(dis[i]);
        }
        bool bad = false;
        if(s.size() == 2){
            bad = true;
        }
        for(int i = mid; i<=n; i++){
            if(adj[i].size() == 1){
                bad = true;
            }
            good[i] = 1;
        }
        dfs(n,0);
        for(int i = mid; i<=n; i++){
            int cnt = 0;
            for(int nxt: adj[i]){
                if(good[nxt]){
                    cnt++;
                }
            }
            if(cnt>=3){
                bad = true;
            }
        }
        if(bad){
            low = mid;
        }
        else{
            high = mid;
        }
        reset(n);
    }
    cout << low << '\n';
    return 0;
}