#include <iostream>
#include <fstream>
#include <vector>
#include <cstring>
using namespace std;
ifstream f("darb.in");
ofstream g("darb.out");
 vector <int> v[100005];
 int n,use[100005],dist[100005],mx=0,nod=1;

 void DFS(int x,int d)
 { int i;
   use[x]=1;
   if (d>mx) {mx=d; nod=x;}

   for(i=0;i<v[x].size();i++)
    if (!use[v[x][i]]) DFS(v[x][i],d+1);
 }

int main()
{ int i,x,y;
   f>>n;
   for(i=1;i<n;i++)
   { f>>x>>y;
     v[x].push_back(y);
     v[y].push_back(x);
   }

   DFS(1,0);
   memset(use,0,sizeof(use));
   DFS(nod,0);
   g<<mx+1<<"\n";
    return 0;
}