#include<cstdio>
#include<vector>
#include<cstring>
#include<queue>
#define pb push_back
using namespace std;
int Max,poz,n,nr,i;
vector<int>v[100001];
int viz[100001];
queue<int>q;
void BFS(int nod)
{
    q.push(nod);
    viz[nod]=1;
    while (!q.empty())
    {
        nod=q.front();
        q.pop();
        vector<int>::iterator it;
        for (it=v[nod].begin();it!=v[nod].end();++it)
        {
            if (viz[*it]==0)
            {
                viz[*it]=viz[nod]+1;
                q.push(*it);
                if (viz[*it]>Max) {Max=viz[*it],poz=*it;}
            }
        }
    }
}
void DFS(int nod)
{
    viz[nod]=1;
    vector<int>::iterator it;
    for (it=v[nod].begin();it!=v[nod].end();++it)
    {
        if (viz[*it]==0)
        {
            ++nr;
            if (nr>Max) Max=nr;
            DFS(*it);
            --nr;
        }
    }
}
int main()
{
    int x,y;
    freopen("darb.in","r",stdin);
    freopen("darb.out","w",stdout);
    scanf("%d",&n);
    for (i=1;i<=n;++i)
    {
        scanf("%d%d",&x,&y);
        v[x].pb(y);
        v[y].pb(x);
    }
    BFS(1);
    memset(viz,0,sizeof(viz));
    nr=1;
    Max=0;
    DFS(poz);
    printf("%d\n",Max);
    return 0;
}