#include<fstream>
#include<vector>
#define N 100100
using namespace std;
ifstream f("darb.in");
ofstream g("darb.out");
vector<int> v[N];
int i,n,x,y,ma,best,t,viz[N];
void dfs(int x)
{
	viz[x]=1;
	++t;
	if(t>ma)
	{
		ma=t;
		best=x;
	}
	for(int i=0;i<v[x].size();++i)
		if(!viz[v[x][i]])
			dfs(v[x][i]);
	--t;
}
int main ()
{
	f>>n;
	for(i=1;i<n;++i)
	{
		f>>x>>y;
		v[x].push_back(y);
		v[y].push_back(x);
	}
	dfs(1);
	memset(viz,0,sizeof(viz));
	dfs(best);
	g<<ma;
	return 0;
}