#include <iostream>
#include <vector>

using namespace std;

vector <int> v;
vector <vector <int>> c;
int a;
vector <int> vis;
int r=0;

void DFS(int n,int h)
{
    if(r<h) r=h;
    for(int i=0;i<c[n].size();i++)
    {
        if(vis[c[n][i]]==0)
        {
            vis[c[n][i]]=1;
            DFS(c[n][i],h+1);
        }
    }
}
int main() {
    int x,y;
    cin >>a;
    v.resize(a+1);
    c.resize(a+1);
    vis.resize(a+1,0);
    for(int i=1;i<a;i++)
    {
        cin >>x>>y;
        c[x].push_back(y);
        c[y].push_back(x);
    }
    vis[1]=1;
    DFS(1,0);
    cout<<r;
}