#include <bits/stdc++.h>
using namespace std;
bool edge_compare(const array<int, 3>& e0, const array<int, 3>& e1) {
  return e0[2] < e1[2];
}
int main() {
  int n, m, k;
  scanf("%d %d %d", &n, &m, &k);
  long long d[800][800];
  for (int i = 0; i < 800; ++i)
    for (int j = 0; j < 800; ++j) d[i][j] = 1LL << 60;
  vector<array<int, 3> > E(m);
  for (array<int, 3>& e : E) scanf("%d %d %d", &e[0], &e[1], &e[2]);
  sort(E.begin(), E.end(), edge_compare);
  if (m > k) {
    E.resize(k);
    m = k;
  }
  n = 0;
  int u, v;
  map<int, int> M;
  map<int, int>::iterator it, end = M.end();
  for (const array<int, 3>& e : E) {
    it = M.find(e[0]);
    u = (it == end) ? M[e[0]] = n++ : it->second;
    it = M.find(e[1]);
    v = (it == end) ? M[e[1]] = n++ : it->second;
    d[u][v] = d[v][u] = e[2];
  }
  for (int i = 0; i < n; ++i) d[i][i] = 0;
  for (int k = 0; k < n; ++k)
    for (int i = 0; i < n; ++i)
      for (int j = 0; j < n; ++j) d[i][j] = min(d[i][j], d[i][k] + d[k][j]);
  vector<long long> paths;
  paths.reserve(n * (n - 1) / 2);
  for (int i = 0; i < n; ++i)
    for (int j = i + 1; j < n; ++j) paths.push_back(d[i][j]);
  nth_element(paths.begin(), paths.begin() + k - 1, paths.end());
  printf("%lld\n", paths[k - 1]);
}
