#include<cstdio>
#include<vector>
#include<cstring>
using namespace std;

int n,x,y,len,viz[100005],nodfinal,nodf;
vector<int> G[100005];

int distmax(int x,int d)
{
    int maxx=d,dd;
    if(d>nodf)
    {
        nodf=d;
        nodfinal=x;
    }
    viz[x]=1;
    for(int i=0;i<G[x].size();i++)
    {
        if(!viz[G[x][i]])
        {
            dd=distmax(G[x][i],d+1);
            if(dd>maxx)
                maxx=dd;
        }
    }
    return maxx;
}

int main()
{
    freopen("darb.in","r",stdin);
    freopen("darb.out","w",stdout);
    scanf("%d",&n);
    for(int i=1;i<n;i++)
    {
        scanf("%d %d",&x,&y);
        G[x].push_back(y);
        G[y].push_back(x);
    }
    memset(viz,0,sizeof(viz));
    distmax(1,0);
    memset(viz,0,sizeof(viz));
    printf("%d",distmax(nodfinal,0)+1);
    return 0;
}