#include <bits/stdc++.h>

using namespace std;

#define N 100005

vector<int> adj[N];

int  dfs(int v,int p){

    int sum=0;

    for(auto &u:adj[v]){

        if(u==p) continue;

        sum=max(dfs(u,v),sum);

    }

    return sum+1;

}

int main(){

    ios::sync_with_stdio(0);

    cin.tie(0);

    int n;

    cin>>n;

    for(int i=0,u,v;i<n-1;i++){

        cin>>u>>v;

        adj[u].push_back(v);

        adj[v].push_back(u);

    }

    queue<int> q;

    q.push(0);

    bool visit[N]={0};

    int temp;

    while(!q.empty()){

        int t=q.front();q.pop();

        visit[t]=1;

        temp=t;

        for(auto &u:adj[t]){

            if(visit[u]) continue;

            q.push(u);

        }

    }

    cout<<dfs(temp,-1)-1;

}