#include <iostream>
#include <fstream>
#include <vector>
#define NMAX 100005
#include <cstring>
using namespace std;
ifstream in("darb.in");
ofstream out("darb.out");
vector <int> arbore[NMAX];
int n,last_level,max_level;
bool viz[NMAX];
void DFS(int nod,int level)
{
    viz[nod]=1;
    if(level>max_level)
    {
        max_level=level;
        last_level=nod;
    }
    for(size_t i=0;i<arbore[nod].size();i++)
    {
        int neighbour=arbore[nod][i];
        if(!viz[neighbour])
            DFS(neighbour,level+1);
    }
}
int main()
{  in>>n;
for(int i=1;i<n;i++)
{
    int x,y;
    in>>x>>y;
    arbore[x].push_back(y);
    arbore[y].push_back(x);
}
DFS(1,0);
memset(viz,0,sizeof(viz));
//out<<max_level;
DFS(last_level,0);
out<<max_level+1;
    return 0;
}