#include <cstdio>
#include <algorithm>
#include <cstring>
#include <vector>
#include <cassert>
#include <unordered_map>
#define pb push_back
using namespace std;
typedef pair<int,int> pp;
struct pt{int u,c;};
typedef vector<int> vec;
typedef vector<pt> vec2;
typedef vector<vec> mat;
typedef vector<vec2> graph;
unordered_map<int,int> ID[200010];
mat dp[2];
graph path;
int N;
int root;
bool chk[200010];
int sum[200010];
int Max[200010][2];
int Maxi[200010][2];
int par[200010];
void input(){
scanf("%d",&N);
path.assign(N+1,vec2());
dp[0].assign(N+1,vec());
dp[1].assign(N+1,vec());
int x,y,z;
for(int i=0;i<N-1;i++){
scanf("%d%d%d",&x,&y,&z);
ID[x][y]=path[x].size();
ID[y][x]=path[y].size();
path[x].pb(pt{y,z});
path[y].pb(pt{x,z});
dp[0][x].pb(-1);dp[1][x].pb(-1);
dp[0][y].pb(-1);dp[1][y].pb(-1);
}
for(int i=1;i<=N;i++){
ID[i][i]=path[i].size();
dp[0][i].pb(-1);
dp[1][i].pb(-1);
}
}
int getMax(int v,vec2& a){
int Max1=-1e9,Max2=-1e9;
int id1=0,id2=0;
for(int i=0;i<a.size();i++){
if(a[i].c>=Max1){
Max2=Max1;
id2=id1;
Max1=a[i].c;
id1=a[i].u;
}else if(a[i].c>Max2){
Max2=a[i].c;
id2=a[i].u;
}
}
Max[v][0]=Max1;Maxi[v][0]=id1;
Max[v][1]=Max2;Maxi[v][1]=id2;
return Max1;
}
void process(int v,int p){
int sz=path[v].size();
int cnt=sz-(v!=root);
int& ret0=dp[0][v][ID[v][p]];
int& ret1=dp[1][v][ID[v][p]];
if(cnt==0){
ret0=0;
ret1=-1e9;
return;
}
vec2 a;
for(int i=0;i<sz;i++){
int u=path[v][i].u;
int c=path[v][i].c;
int id=ID[u][v];
if(p==u)continue;
int z = max(dp[0][u][id],dp[1][u][id]+c);
sum[v]+=z;
a.pb(pt{u,dp[0][u][id]+c-z});
}
ret0=ret1=sum[v];
ret1+=getMax(v,a);
}
void dfs(int v,int p){
int& ret=dp[0][v][ID[v][p]];
if(~ret)return;
par[v]=p;
for(int i=0;i<path[v].size();i++){
int u=path[v][i].u;
if(u==p)continue;
dfs(u,v);
}
process(v,p);
// printf("%d %d %d : %d\n",v,p,mode,dp[mode][v][ID[v][p]]);
}
void process2(int v,int p){
int sz=path[v].size();
int cnt=sz-1;
int& ret0=dp[0][v][ID[v][p]];
int& ret1=dp[1][v][ID[v][p]];
if(cnt==0){
ret0 = 0;
ret1 = -1e9;
return;
}
if(v==p)return;
int id=ID[p][v];
int c=path[p][id].c;
int z=0;
ret0 = ret1 = sum[v] - max(dp[0][p][id],dp[1][p][id]+c);
if(v!=root){
id = ID[par[v]][v];
c = path[par[v]][id].c;
z = max(dp[0][par[v]][id],dp[1][par[v]][id]+c);
ret0 += z;
ret1 += z;
if(Maxi[v][0]!=p){
ret1+=max(Max[v][0],dp[0][par[v]][id]+c-z);
}else{
ret1+=max(Max[v][1],dp[0][par[v]][id]+c-z);
}
}else{
if(Maxi[v][0]!=p){
ret1+=Max[v][0];
}else{
ret1+=Max[v][1];
}
}
}
void dfs2(int v,int p){
int& ret=dp[0][v][ID[v][p]];
if(~ret)return;
if(v==root){
process2(v,p);
return;
}
dfs2(par[v],v);
if(v!=p)process2(v,p);
// printf("%d %d %d : %d\n",v,p,mode,dp[mode][v][ID[v][p]]);
}
int process3(int v){
int ret=0;
int sz=path[v].size();
for(int i=0;i<sz;i++){
int u=path[v][i].u;
int c=path[v][i].c;
int id=ID[u][v];
int z = max(dp[0][u][id],dp[1][u][id]+c);
ret+=z;
}
return ret;
}
void PS(){
for(int i=1;i<=N;i++){
for(int j=0;j<2;j++){
Max[i][j]=-1e9;
}
}
root=1;
int ans=0;
dfs(1,1);
for(int i=2;i<=N;i++){
if(path[i].size()==1)dfs2(i,i);
}
for(int i=1;i<=N;i++){
ans=max(ans,process3(i));
}
printf("%d\n",ans);
}
int main(){
input();
PS();
return 0;
}
