#include <bits/stdc++.h>
using namespace std;
const int N = 200000 + 7;
int n, m, k;
vector<pair<long long, int> > e[N];
struct path {
  int st, ed, inx;
  long long dis;
  bool operator<(const path &k) const { return dis > k.dis; }
};
priority_queue<path> q;
map<pair<int, int>, int> dic;
int main() {
  scanf("%d%d%d", &n, &m, &k);
  for (int i = 1, u, v, w; i <= m; ++i)
    scanf("%d%d%d", &u, &v, &w), e[u].push_back(make_pair(1ll * w, v)),
        e[v].push_back(make_pair(1ll * w, u));
  for (int i = 1; i <= n; ++i)
    sort(e[i].begin(), e[i].end()), q.push((path){i, i, 0, e[i][0].first}),
        dic[make_pair(i, i)] = 1;
  k <<= 1;
  while (!q.empty()) {
    path s = q.top();
    q.pop();
    if (!dic[make_pair(s.st, e[s.ed][s.inx].second)]) {
      dic[make_pair(s.st, e[s.ed][s.inx].second)] = 1;
      if (--k == 0) return printf("%lld", s.dis), 0;
      q.push((path){s.st, e[s.ed][s.inx].second, 0,
                    s.dis + e[e[s.ed][s.inx].second][0].first});
    }
    if (s.inx + 1 < (int)e[s.ed].size())
      q.push((path){s.st, s.ed, s.inx + 1,
                    s.dis - e[s.ed][s.inx].first + e[s.ed][s.inx + 1].first});
  }
  return 0;
}
