#include<cstdio>
#include<cstring>
#include<vector>
#define NMax 100004
using namespace std;

int viz[NMax],maxi,fst;
vector<int> vc[NMax];

void df (int nod, int dist)
{
    viz[nod]=1;
    if (dist>maxi)
        maxi=dist, fst=nod;
    for (int i=0; i<vc[nod].size(); i++)
        if (!viz[vc[nod][i]])
            df(vc[nod][i],dist+1);
}

int main ()
{
    int i,N,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);
        vc[x].push_back(y);
        vc[y].push_back(x);
    }
    df(1,0);
    memset(viz,0,sizeof(viz));
    maxi=0;
    df(fst,0);
    printf("%d\n",maxi+1);
    return 0;
}