#include <bits/stdc++.h>
using namespace std;
using ll = long long;

template <class T, class F>
T LowerBound(T i0, T i1, F f) {
    while (i0 < i1) {
        T i = i0 + (i1 - i0) / 2;
        if (f(i)) i1 = i; else i0 = i + 1;
    }
    return i0;
}

int c0;

struct Graph {
    static constexpr int INF = 1 << 30;
    struct Vertex { int n, c; };
    struct Edge { int i, n, c; };
    Graph(int n) : v(n, { -1, INF }), n(n), m(0) {}
    void add_edge(int i, int j, int c) {
        e.push_back({ j, v[i].n, c });
        v[i].n = m;
        m++;
    }
    void bfs01(int s, int t) {
        vector<int> st[2];
        st[0].push_back(s);
        for (int i = 0; i < n; i++) v[i].c = INF;
        v[s].c = 0;
        while (!st[0].empty() || (swap(st[0], st[1]), !st[0].empty())) {
            int i = st[0].back(); st[0].pop_back();
            if (i == t) break;
            for (int j = v[i].n; j >= 0; j = e[j].n) {
                Edge &o = e[j];
                int oc = o.c > c0;
                int c = v[i].c + oc;
                if (c < v[o.i].c) {
                    v[o.i].c = c;
                    st[oc].push_back(o.i);
                }
            }
        }
    }
    vector<Vertex> v;
    vector<Edge> e;
    int n, m;
};

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    int n, m, k;
    cin >> n >> m >> k;

    Graph g(n);
    for (int i = 0; i < m; i++) {
        int u, v, c;
        cin >> u >> v >> c;
        u--; v--;

        g.add_edge(u, v, c);
        g.add_edge(v, u, c);
    }

    auto c = LowerBound<int>(0, (int)2e5, [&](auto c) {
        c0 = c;
        g.bfs01(0, n - 1);
        return g.v[n - 1].c < k;
    });
    cout << c << endl;

    return 0;
}