#include<bits/stdc++.h>
using namespace std;
signed main(){cin.tie(0)->sync_with_stdio(0);
int n;cin>>n;vector<vector<int>>e(n);
if(n%2==0)return cout<<n,0;
for(int i=0;i<n-1;++i){
	int u,v;cin>>u>>v;--u,--v;
	e[u].push_back(v),e[v].push_back(u);
}
vector<int>d(n),s,p(n),q(n),r(n),t(n);
auto dfs=[&](auto&self,int u,int f)->void{
	static int z=-1;p[u]=++z,r[z]=u;t[u]=max(t[u],u);
	if(d[u]==2)s.push_back(u);
	for(int v:e[u])if(v!=f){
		t[v]=u;
		d[v]=d[u]+1;
		self(self,v,u);
		t[u]=max(t[u],t[v]);
	}
	q[u]=z;
};dfs(dfs,n-1,-1);
int ans=-1;
set<int>k;
for(int i=0;i<n;++i)if(d[i]!=0&&d[i]%2==0)k.insert(t[i]);
for(int i=0;i<n;++i)if(e[i].size()==1||d[i]%2==1)ans=max(ans,i);
if(k.size()>=3)ans=max(ans,*++(++k.rbegin()));
for(int u:s){
	k.clear();
	for(int i=p[u]+1;i<=q[u];++i){
		int v=r[i];
		if(d[v]%2==0)k.insert(t[v]);
	}
	if(k.size()>=2)ans=max(ans,*++k.rbegin());
}
cout<<ans+1;
}