#include <bits/stdc++.h>
#define eb emplace_back
#define sz(V) ((int)(V).size())
#define allv(V) ((V).begin()),((V).end())
#define upmax(a,b) (a)=max((a),(b))
#define INFLL (0x3f3f3f3f3f3f3f3fll)
using namespace std;
typedef long long ll;
const int MAXN = 200055;
ll D[MAXN], E[MAXN];
vector<int> G[MAXN];
int A[MAXN], B[MAXN], C[MAXN];
ll Ans;
int N;
void f(int i, int p, int pe) {
D[i] = 0; E[i] = -INFLL;
for(int e : G[i]) {
int v = A[e]^B[e]^i;
if(v == p) continue;
f(v, i, C[e]);
upmax(E[i], -max(D[v], E[v]) + D[v] + C[e]);
D[i] += max(D[v], E[v]);
}
E[i] += D[i] + pe;
}
int main() {
ios::sync_with_stdio(false);
cin >> N;
for(int i = 1; i < N; i++) {
cin >> A[i] >> B[i] >> C[i];
G[A[i]].eb(i);
G[B[i]].eb(i);
}
vector<int> O;
for(int i = 1; i <= N; i++) O.eb(i);
random_shuffle(allv(O));
for(int t = 0; t < N && t <= 1000; t++) {
int i = O[t];
ll ret = 0;
for(int e : G[i]) {
int v = A[e]^B[e]^i;
f(v, i, C[e]);
ret += max(D[v], E[v]);
}
upmax(Ans, ret);
}
cout << Ans << endl;
return 0;
}
