#include <bits/stdc++.h>
#define ll long long
#define db long double
#define II pair <ll,ll>
#define III pair <ll,II>
#define IV pair <vector <int>,vector <int> >
#define fst first
#define snd second
#define BIT(x,i) ((x>>i)&1)
#define pi acos(-1)
#define to_radian(x) (x*pi/180.0)
#define to_degree(x) (x*180.0/pi)
#define Log(x) (31-__builtin_clz((int)x))
#define LogLL(x) (63-__builtin_clzll((ll)x))
#define mxn 100005
#include "dreaming.h"
using namespace std;
struct International_Olympiad_in_Informatics
{
vector <II> a[mxn];
int n,m,i,mi,mx_each,w[mxn],comp,f[mxn],u,v,k;
void dfs(int u,int p)
{
vector <int> vec;
vec.push_back(0); vec.push_back(0);
for(II adj:a[u])
{
int v=adj.fst,k=adj.snd;
if(v==p) continue;
dfs(v,u);
vec.push_back(f[v]+k);
}
sort(vec.rbegin(),vec.rend());
f[u]=vec[0];
}
void DFS(int u,int p)
{
vector <int> vec;
vec.push_back(0); vec.push_back(0);
for(II adj:a[u])
{
int v=adj.fst,k=adj.snd;
vec.push_back(f[v]+k);
}
sort(vec.rbegin(),vec.rend());
mx_each=max(mx_each,vec[0]+vec[1]);
f[u]=vec[0];
mi=min(mi,f[u]);
for(II adj:a[u])
{
int v=adj.fst,k=adj.snd;
if(v==p) continue;
f[u]=vec[vec[0]==f[v]+k];
DFS(v,u);
}
}
int Work(int _n,int m,int l,int U[],int V[],int W[])
{
n=_n;
for(i=0;i<m;i++)
{
u=U[i]; v=V[i]; k=W[i];
u++; v++;
a[u].push_back({ v,k }); a[v].push_back({ u,k });
}
memset(f,-1,sizeof(f));
mx_each=0;
for(u=1;u<=n;u++)
if(f[u]==-1)
{
mi=round(2e9);
dfs(u,0);
DFS(u,0);
w[++comp]=mi;
}
sort(w+1,w+comp+1);
if(comp==1) return mx_each;
if(comp==2) return max(mx_each,w[1]+w[2]+l);
return max(mx_each,max(w[comp-1]+w[comp]+l,w[comp-2]+w[comp-1]+2*l));
}
} IOI;
int travelTime(int _n,int m,int l,int U[],int V[],int W[])
{
return IOI.Work(_n,m,l,U,V,W);
}
/*
int main()
{
freopen("dreaming.inp","r",stdin);
freopen("dreaming.out","w",stdout);
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int n,m,l,U[102],V[102],W[102];
cin>>n>>m>>l;
for(int i=0;i<m;i++) cin>>U[i];
for(int i=0;i<m;i++) cin>>V[i];
for(int i=0;i<m;i++) cin>>W[i];
cout<<travelTime(n,m,l,U,V,W);
}
*/
