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

#define pb push_back
#define ll long long
#define ld long double
#define F first
#define S second

const ll inf = 2e12;


int main() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#else
    freopen("phoneline.in", "r", stdin);
    freopen("phoneline.out", "w", stdout);
#endif
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    ll n, m, k;
    cin >> n >> m >> k;
    vector <pair <ll ,ll > > g[n];
    vector <ll> rib;
    for (ll i = 0; i < m; i++){
        ll x, y, z;
        cin >> x >> y >> z;
        x --;
        y --;
        g[x].pb({y, z});
        g[y].pb({x, z});
        rib.pb(z);
    }
    rib.pb(0);
    sort (rib.begin() , rib.end());
    ll l = 0, r = m;
    while (l + 1 < r){
        ll mid = (l + r) / 2;
        priority_queue <pair <ll ,ll> > q;
        q.push({0 , 0});
        vector <ll> d(n, inf);
        d[0] = 0;
        while (!q.empty()){
            ll rast = -q.top().F , v = q.top().S;
            q.pop();
            if (rast > d[v])continue;
            for (auto to : g[v]){
                if (d[v] + (to.S > mid) < d[to.F]){
                    d[to.F] = d[v] + (to.S > mid);
                    q.push({-d[to.F] , to.F});
                }
            }
        }
        if (d[n - 1] > k){
            l = mid + 1;
        }
        else{
            r = mid;
        }
    }
    for (ll i = l; i <= r; i++){
        priority_queue <pair <ll ,ll> > q;
        q.push({0 , 0});
        vector <ll> d(n, inf);
        d[0] = 0;
        while (!q.empty()){
            ll rast = -q.top().F , v = q.top().S;
            q.pop();
            if (rast > d[v])continue;
            for (auto to : g[v]){
                if (d[v] + (to.S > i) < d[to.F]){
                    d[to.F] = d[v] + (to.S > i);
                    q.push({-d[to.F] , to.F});
                }
            }
        }
        if (d[n - 1] <= k){
            cout << i << endl;
            return 0;
        }
    }
    cout << "-1" << endl;
}