#include<bits/stdc++.h>
using namespace std;
long long read(void)
{
	char ch=getchar();long long sum=0;bool f=0;
	while((ch<'0'||ch>'9')&&ch!='-')ch=getchar();
	if(ch=='-')f=1,ch=getchar();
	while(ch>='0'&&ch<='9')sum=sum*10+ch-'0',ch=getchar();
	if(f)sum=-sum;return sum;
}
const int N=101000;
int n;
bool tg[N];
int dep[N],is[N];
vector<int>G[N];
bool DFS(int u,int f){
	bool fl=1;
	int cnt=0;is[u]=tg[u];dep[u]=dep[f]+1;
	if(tg[u]&&((dep[u]-1)&1))return 0;
	for(int v:G[u])if(v!=f){
		fl&=DFS(v,u);cnt+=is[v];
		is[u]|=is[v];
	}
	if(u!=n&&dep[u]%2==0&&cnt>=2)fl=0;
	if(u==n&&cnt>=3)fl=0;
	return fl;
	
}
bool chk(int t){
	for(int i=1;i<=n;i++)tg[i]=(i>=t),is[i]=0;
	return DFS(n,0)^1;
}
int main()
{
	n=read();
	for(int i=1,x,y;i<=n-1;i++)x=read(),y=read(),G[x].push_back(y),G[y].push_back(x);
	if(!(n&1))return cout<<n,0;
	int L=1,R=n;
	while(L<R){
		int mid=(L+R+1)>>1;
		if(chk(mid))L=mid;
		else R=mid-1;
	}cout<<L;
	return 0;
	
}