#include <bits/stdc++.h>
#ifndef cpismylifeOwO
#include "dreaming.h"
#endif // cpismylifeOwO
using namespace std;
const long long mod = 1e9 + 7;
const int MaxN = 1e6 + 5;
int ni, mi, li;
int Ai[MaxN];
int Bi[MaxN];
int Ti[MaxN];
#ifdef cpismylifeOwO
void Inp()
{
cin >> ni >> mi >> li;
for (int x = 0; x < mi; x++)
{
cin >> Ai[x] >> Bi[x] >> Ti[x];
}
}
#endif // cpismylifeOwO
struct Edge
{
int u, v, w;
};
int n, m, l;
Edge edges[MaxN];
vector<int> graph[MaxN];
int best[MaxN];
int secbest[MaxN];
int bestpos[MaxN];
int F[MaxN];
bool visited[MaxN];
vector<int> cur;
void DFS(int u, int p)
{
visited[u] = true;
cur.push_back(u);
best[u] = 0;
secbest[u] = -1e9;
bestpos[u] = 0;
for (int x : graph[u])
{
int v = edges[x].u ^ edges[x].v ^ u, w = edges[x].w;
if (v != p)
{
DFS(v, u);
if (best[u] < best[v] + w)
{
secbest[u] = best[u];
best[u] = best[v] + w;
bestpos[u] = v;
}
else if (secbest[u] < best[v] + w)
{
secbest[u] = best[v] + w;
}
}
}
}
void Reroot(int u, int p, int pre)
{
F[u] = max(best[u], pre);
for (int x : graph[u])
{
int v = edges[x].u ^ edges[x].v ^ u, w = edges[x].w;
if (v != p)
{
if (bestpos[u] == v)
{
Reroot(v, u, max(pre, secbest[u]) + w);
}
else
{
Reroot(v, u, max(pre, best[u]) + w);
}
}
}
}
priority_queue<pair<int, int>> pq;
int travelTime(int N, int M, int L, int A[], int B[], int T[])
{
n = N;
m = M;
l = L;
for (int x = 1; x <= m; x++)
{
edges[x].u = A[x - 1] + 1;
edges[x].v = B[x - 1] + 1;
edges[x].w = T[x - 1];
graph[edges[x].u].push_back(x);
graph[edges[x].v].push_back(x);
}
for (int x = 1; x <= n; x++)
{
if (!visited[x])
{
cur.clear();
DFS(x, -1);
Reroot(x, -1, 0);
pair<int, int> mi = make_pair(F[cur[0]], cur[0]);
for (int x : cur)
{
mi = min(mi, make_pair(F[x], x));
}
pq.push(mi);
}
}
pair<int, int> cur = pq.top();
pq.pop();
while (!pq.empty())
{
pair<int, int> now = pq.top();
pq.pop();
m++;
edges[m].u = cur.second;
edges[m].v = now.second;
//cout << edges[m].u << " " << edges[m].v << "\n";
edges[m].w = l;
graph[edges[m].u].push_back(m);
graph[edges[m].v].push_back(m);
}
DFS(1, -1);
Reroot(1, -1, 0);
int res = 0;
for (int x = 1; x <= n; x++)
{
res = max(res, F[x]);
}
return res;
}
#ifdef cpismylifeOwO
void Exc()
{
cout << travelTime(ni, mi, li, Ai, Bi, Ti);
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int test = 1;
//cin >> test;
for (int x = 1; x <= test; x++)
{
Inp();
Exc();
}
return 0;
}
#endif // cpismylifeOwO
