#include <cstdio>
#include <cstring>
#include <vector>
#include <algorithm>
#include <unordered_map>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define X first
#define Y second
#define PB push_back
using namespace std;
typedef pair < int, int > pii;
typedef long long ll;
const int N = 2e5 + 500;
const int INF = 2e9;
vector < int > g[N];
int dp[2][2 * N], zbr[N];
vector < pair < int, int > > kand[N];
int n, jesam[N], u[N], v[N], vr[N];
int f(int x, int fl, int brd){
if(dp[fl][2 * brd + (u[brd] == x)] != -1)
return dp[fl][2 * brd + (u[brd] == x)];
//char c; scanf("%c", &c);
int lst = x;
if(brd < n){
lst = u[brd];
if(u[brd] == x)
lst = v[brd];
}
//printf("x = %d fl = %d lst = %d brd = %d\n", x, fl, lst, brd);
if(jesam[x] == -1){
int sm = 0;
for(int nxt : g[x]){
int cv = (u[nxt] == x ? v[nxt] : u[nxt]);
if(cv == lst) continue;
int opt = max(f(cv, 0, nxt), f(cv, 1, nxt) + vr[nxt]);
sm += opt;
kand[x].PB({f(cv, 0, nxt) + vr[nxt] - opt, cv});
}
kand[x].PB({-INF, -1});
sort(kand[x].rbegin(), kand[x].rend());
jesam[x] = (x == lst ? -2 : brd); zbr[x] = sm;
//printf("x = %d fl = %d lst = %d --> %d + %d\n", x, fl, lst, sm, kand[x][0].X);
//printf("jesam[ %d ] = %d\n", x, jesam[x]);
return dp[fl][2 * brd + (u[brd] == x)] = sm + kand[x][0].X * (fl == 1);
}
if(jesam[x] >= 0 && (u[jesam[x]] == lst || v[jesam[x]] == lst) && lst != x){
return dp[fl][2 * brd + (u[brd] == x)] = zbr[x] + kand[x][0].X * (fl == 1);
}
if(jesam[x] != -2){
int cv = u[jesam[x]];
if(cv == x)
cv = v[jesam[x]];
//printf("tu sam cv = %d\n", cv);
int opt = max(f(cv, 0, jesam[x]), f(cv, 1, jesam[x]) + vr[jesam[x]]);
zbr[x] += opt;
kand[x].PB({f(cv, 0, jesam[x]) + vr[jesam[x]] - opt, cv});
sort(kand[x].rbegin(), kand[x].rend());
jesam[x] = -2;
}
int sm = zbr[x] - (x == lst ? 0 : max(f(lst, 0, brd), f(lst, 1, brd) + vr[brd]));
int dod = kand[x][0].X;
if(kand[x][0].Y == lst)
dod = kand[x][1].X;
//printf("x = %d fl = %d lst = %d --> %d + %d\n", x, fl, lst, sm , dod * (fl == 1));
return dp[fl][2 * brd + (u[brd] == x)] = sm + dod * (fl == 1);
}
int main(){
memset(dp, -1, sizeof(dp));
memset(jesam, -1, sizeof(jesam));
scanf("%d", &n);
for(int i = 1;i < n;i++){
int x, y, z; scanf("%d%d%d", &x, &y, &z);
g[x].PB(i), g[y].PB(i);
u[i] = x, v[i] = y, vr[i] = z;
}
int sol = 0;
for(int i = 1;i <= n;i++)
sol = max(sol, f(i, 0, n + i));
printf("%d\n", sol);
return 0;
}
