#include <bits/stdc++.h>
using namespace std;
const int kn = 2e5 + 69;
map<pair<int, int>, int> used;
int n, m, k, cnt = 0;
vector<pair<int, long long> > G[kn];
pair<long long, pair<int, int> > edge[kn];
priority_queue<pair<long long, pair<int, int> >,
               vector<pair<long long, pair<int, int> > >,
               greater<pair<long long, pair<int, int> > > >
    pq;
int main() {
  scanf("%d %d %d", &n, &m, &k);
  for (int hi = 1; hi <= m; hi++) {
    int u, v;
    long long w;
    scanf("%d %d %lld", &u, &v, &w);
    edge[hi] = {w, {u, v}};
  }
  sort(edge + 1, edge + m + 1);
  for (int i = 1; i <= min(k, m); i++) {
    int u = edge[i].second.first, v = edge[i].second.second;
    long long w = edge[i].first;
    G[u].push_back({v, w});
    G[v].push_back({u, w});
    pq.push({w, {u, v}});
    used[{min(u, v), max(u, v)}] = w;
  }
  for (int i = 1; i <= n; i++) used[{i, i}] = -1;
  while (pq.size()) {
    int u = pq.top().second.first, v = pq.top().second.second;
    long long dis = pq.top().first;
    pq.pop();
    if (used[{min(u, v), max(u, v)}] == -1) continue;
    cnt++;
    if (cnt == k) {
      printf("%lld", dis);
      return 0;
    }
    used[{min(u, v), max(u, v)}] = -1;
    for (pair<int, long long> tmp : G[u]) {
      int p = tmp.first;
      long long W = tmp.second;
      if ((not used.count({min(p, v), max(p, v)})) ||
          used[{min(p, v), max(p, v)}] > dis + W) {
        used[{min(p, v), max(p, v)}] = dis + W;
        pq.push({dis + W, {p, v}});
      }
    }
    for (pair<int, long long> tmp : G[v]) {
      int p = tmp.first;
      long long W = tmp.second;
      if ((not used.count({min(p, u), max(p, u)})) ||
          used[{min(p, u), max(p, u)}] > dis + W) {
        used[{min(p, u), max(p, u)}] = dis + W;
        pq.push({dis + W, {p, u}});
      }
    }
  }
}
