#include "stdio.h"
#include "stdlib.h"
#include "math.h"
#include "string.h"
#include "stdint.h"
#include "vector"
#include "set"
#include "stack"
#include "queue"
#include "map"
#include "algorithm"
#define min(a,b) (a)<(b)?(a):(b)
#define max(a,b) (a)>(b)?(a):(b)
#define abso(a) (a)>(0)?(a):(-a)
#define VI vector<int>
#define pb push_back
#define all(c) c.begin(), c.end()
#define lli long long int
using namespace std;

int inline inp()
{
    int n=0;
    char c=getchar_unlocked();
    while(c < '0' || c >'9') {c=getchar_unlocked();}
    while(c>='0' && c<='9')
    {
    n=(n<<3)+(n<<1)+c-'0';
    c=getchar_unlocked();
    }
    return n;
}

vector< vector< int > > graph;
bool visited[10010];
int length[10010], len, idx;


void BFS(int src)
{
    memset(visited,false, sizeof(visited));
    visited[src] = true;
    len = 0;
    length[src] = len;

    queue<int> Q;
    Q.push(src);

    while(!Q.empty())
    {
        int cur = Q.front();
        Q.pop();

        for (VI::iterator it = graph[cur].begin(); it != graph[cur].end(); ++it)
        {
            if(!visited[*it])
            {
                visited[*it] = true;
                Q.push(*it);
                length[*it] = length[cur]+1;
            }
        }
    }

}
int main()
{
	int n = inp();
    graph = vector< VI > (n);
    int p,q, flag = 0;
    for (int i = 0; i < n-1; ++i)
    {
        p = inp();
        q = inp();
        p--;
        q--;
        graph[p].pb(q);
        graph[q].pb(p);
    }


    //checking for connected components

    BFS(0);

    int maxi = 0,idx;

    for (int i = 0; i < n; ++i)
    {
        if(length[i] > maxi)
        {
            maxi = length[i];
            idx = i;
        }
      //  printf("%d ",length[i] );
    }
    //printf("\n");


    //printf("doing bfs for %d\n",idx );
    BFS(idx);

    maxi = 0;
    for (int i = 0; i < n; ++i)
    {
        if(length[i] > maxi)
        {
            maxi = length[i];
            idx = i;
        }
    //    printf("%d ",length[i] );
    }
    //printf("\n");
    printf("%d\n",maxi );

	return 0;
}