#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")

#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
using namespace __gnu_pbds;

typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;


template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;

#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)

#define sz(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound
#define all(x) x.begin(), x.end()
#define shandom_ruffle random_shuffle

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 100001; //check the limits, dummy

struct data {
    ll weight; int start, last, index;
    data(ll w, int S, int L, int I) {
        weight = w; start = S; last = L; index = I;
    }
    bool operator<(data other) const
    {
        return weight > other.weight;
    }
};


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

    int N, M, K; //cin >> N >> M >> K;
    N = 100000; M = 200000;
    K = 100000;
    vector<vpl> graph(N);
    F0R(i, N-1) {
        ll A, B, C;
        A = i; B = i+1;
        C = uniform_int_distribution<int>(1, 1000000000)(rng);
        graph[A].pb(mp(C, B));
        graph[B].pb(mp(C, A));
    }
    FOR(i, N-1, M) {
        ll A, B, C;
        A = uniform_int_distribution<int>(0, N-2)(rng);
        B = uniform_int_distribution<int>(A+1, N-1)(rng);
        C = uniform_int_distribution<int>(1, 1000000000)(rng);
        graph[A].pb(mp(C, B));
        graph[B].pb(mp(C, A));
    }

    F0R(i, N) {
        sort(all(graph[i]));
    }

    priority_queue<data> pq; //-weight, edge index, start, next-to-last.
    K *= 2;
    set<pl> visited;
    F0R(i, N) {
        pq.push(data(graph[i][0].f, i, i, 0));
        visited.insert(mp(i, i));
    }

    while (!pq.empty()) {
        data cur = pq.top();
        pq.pop();
        int nxt = graph[cur.last][cur.index].s;
        if (!visited.count(mp(cur.start, graph[cur.last][cur.index].s))) {
            visited.insert(mp(cur.start, graph[cur.last][cur.index].s));
            //cout << cur.start << " " << nxt << " " << cur.weight << endl;
            K--;
            if (K == 0) {
                cout << cur.weight << endl; return 0;
            }
            pq.push(data(cur.weight + graph[nxt][0].f, cur.start, nxt, 0));
        }
        if (cur.index + 1 < sz(graph[cur.last])) {
            pq.push(data(cur.weight - graph[cur.last][cur.index].f + graph[cur.last][cur.index + 1].f, cur.start, cur.last, cur.index + 1));
        }

    }

    return 0;
}

// read the question correctly (ll vs int)
// template by bqi343