#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
using ll =  long long ;
using P = pair<ll,ll> ;
const ll INF = 1e18;
const int MOD = 1000000007;
int n = 100005;
vector<vector<int>> tree(n,vector<int>());
int mx = 0,id = 0;

void dfs(int i,int p=-1,int d=0){
    if(d > mx) mx = d,id = i;
    for(int c:tree[i]){
        if(c == p) continue;
        dfs(c,i,d+1);
    }
}

int main(){
    cin >> n;
    rep(i,n-1){
        int a,b;
        cin >> a >> b;
        --a;--b;
        tree[a].push_back(b);
        tree[b].push_back(a);
    }   
    dfs(0);
    dfs(id);
    cout << n-1-mx << endl;
    return 0;
}