#include <bits/stdc++.h>
using namespace std;
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define _ << " " <<
#define lf "\n"
#define ff endl
#ifndef EVAL
#define infor(fmt, ...) do { fprintf(stderr, fmt, ##__VA_ARGS__); } while(0)
#define infof(fmt, ...) do { fprintf(stderr, fmt"\n", ##__VA_ARGS__); } while(0)
#else
#define infor(...)
#define infof(...)
#endif
using ll = long long;
int tunnel(int N, int M, int L, vector<int> A, vector<int> B, vector<int> C) {
vector<vector<array<int, 2>>> adj(N);
for(int i = 0; i < M; ++i) {
adj[A[i]].push_back({B[i], C[i]});
adj[B[i]].push_back({A[i], C[i]});
}
vector<int> d(N);
vector<int> st(N);
vector<bool> vis(N);
auto dfs = [&](int v, auto &&dfs) -> void {
st[v] = d[v];
vis[v] = 1;
for(auto [u, w]: adj[v]) {
if(vis[u]) continue;
d[u] = w + d[v];
dfs(u, dfs);
st[v] = max(st[v], st[u]);
}
};
for(int i = 0; i < N; ++i)
if(!vis[i]) dfs(i, dfs);
fill(all(vis), 0);
auto reroot = [&](int v, int up, auto &&reroot) -> int {
infof("... reroot(%d, %d)", v, up);
vis[v] = 1;
vector<array<int, 2>> ups = {{max(up, 0), v}};
for(auto [u, w]: adj[v]) {
if(vis[u]) continue;
ups.push_back({st[u] - d[u] + w, u});
}
infor("ups[%d]:");
for(auto [x, n]: ups)
infor(" (%d, %d)", x, n);
infof("");
sort(rall(ups));
int mn = max(st[v] - d[v], up);
for(auto [u, w]: adj[v]) {
if(vis[u]) continue;
int up_u = ups[0][1] != u ? ups[0][0] : ups[1][0];
infof("... - calling %d with up_u = %d + w", u, up_u);
mn = min(mn, reroot(u, up_u + w, reroot));
}
return mn;
};
vector<int> c;
for(int i = 0; i < N; ++i) {
if(!vis[i]) infof("------");
if(!vis[i]) c.push_back(reroot(i, 0, reroot));
}
infor("c:");
for(auto x: c)
infor(" %d", x);
infof("");
sort(rall(c));
int ans = c[0];
if(c.size() > 1)
ans = max(ans, c[0] + c[1] + L);
if(c.size() > 2)
ans = max(ans, c[1] + c[2] + 2 * L);
infof("=============");
fill(all(vis), 0);
auto diam = [&](int v, int f, auto &&diam) -> array<int, 2> {
vis[v] = 1;
array<int, 2> mx = {0, v};
for(auto [u, w]: adj[v]) {
if(u == f) continue;
auto sus = diam(u, v, diam);
sus[0] += w;
mx = max(mx, sus);
}
return mx;
};
for(int i = 0; i < N; ++i) {
if(vis[i]) continue;
auto [_x, j] = diam(i, -1, diam);
auto [x, _j] = diam(j, -1, diam);
infof("diam[%d] is %d", i, x);
ans = max(ans, x);
}
return ans;
}
#ifndef EVAL
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
int N, M, L; cin >> N >> M >> L;
vector<int> A(M), B(M), C(M);
for (int i = 0; i < M; i ++) cin >> A[i] >> B[i] >> C[i];
cout << tunnel(N, M, L, A, B, C) << '\n';
}
#endif
