#include <bits/stdc++.h>
#define mp make_pair
#define pb push_back
#define pf push_front
#define ll long long
#define ull unsigned long long
#define x first
#define y second
#define pi pair<int,int>
#define pl pair<ll,ll>

using namespace std;
ifstream fin("darb.in");
ofstream fout("darb.out");

const ll N=1e5+5,INF=1e18,MOD=666013,M=1e2+5,inf=INT_MAX;

int n,m;
int maxim,node;
vector<int> adj[N];

void dfs(int nod,int dist,int par)
{
    for(int i=0;i<adj[nod].size();i++)
    {
        int vec=adj[nod][i];
        if(par!=vec)dfs(vec,dist+1,nod);
    }
    if(dist>maxim)
    {
        maxim=dist;
        node=nod;
    }
}

int main()
{
    fin>>n;
    for(int i=1;i<n;i++)
    {
        int a,b;
        fin>>a>>b;
        adj[a].pb(b);
        adj[b].pb(a);
    }
    dfs(1,1,0);
    dfs(node,1,0);
    fout<<maxim;

}