#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define rep(i,n) for(int i=0;i<n;i++)
#define chmin(k,m) k = min(k,m)
#define chmax(k,m) k = max(k,m)
#define Pr pair<ll,ll>
#define riano_ std::ios::sync_with_stdio(false);std::cin.tie(nullptr)
using Graph = vector<vector<Pr>>;

multiset<ll> in,out;
ll tmp = 2e18;

//dfs
//s:始点 i:dfs回数 t:始点からの距離
vector<int> vis;
void dfs_insert(Graph &G, int s,int i,int fbd){
    for(auto[nx,c]:G[s]){
        if(vis[nx]==i) continue;
        if(nx==fbd) continue;
        vis[nx] = i;
        out.insert(c);
        dfs_insert(G,nx,i,fbd);
    }
}

void dfs_calc(Graph &G, int s,int i,int fbd){
    auto itr = in.end(); itr--; ll y = *itr;
    itr = in.begin(); ll x = *itr;
    itr = out.end(); itr--; ll z = *itr;
    chmin(tmp,max(z,y-x));
    for(auto[nx,c]:G[s]){
        if(vis[nx]==i) continue;
        if(nx==fbd) continue;
        vis[nx] = i;
        out.erase(out.find(c));
        in.insert(c);
        dfs_calc(G,nx,i,fbd);
        in.erase(in.find(c));
        out.insert(c);
    }
}
    
int main() {
    riano_; ll ans = 0;
    ll N; cin >> N;
    Graph G(N+1);
    ll ma,mb,mc = 0;
    rep(i,N-1){
        ll a,b,c; cin >> a >> b >> c;
        G[a].emplace_back(b,c); G[b].emplace_back(a,c);
        if(c>mc){
            mc = c; ma = a; mb = b;
        }
    }
    
    vis.assign(N+1,-1);
    in.insert(mc); out.insert(0);
    vis[ma] = 0; dfs_insert(G,ma,0,mb);
    vis[ma] = 1; dfs_calc(G,ma,1,mb);
    chmax(ans,tmp);

    swap(ma,mb); in.clear(); out.clear(); tmp = 2e18;
    vis.assign(N+1,-1);
    in.insert(mc); out.insert(0);
    vis[ma] = 0; dfs_insert(G,ma,0,mb);
    vis[ma] = 1; dfs_calc(G,ma,1,mb);
    chmax(ans,tmp);

    cout << ans << endl;
}