#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }
#define COLOR(s) ("\x1b[" s "m")


vector<int> uf;
int root(int u) {
  return (uf[u] < 0) ? u : (uf[u] = root(uf[u]));
}
bool connect(int u, int v) {
  u = root(u);
  v = root(v);
  if (u == v) return false;
  if (uf[u] > uf[v]) swap(u, v);
  uf[u] += uf[v];
  uf[v] = u;
  return true;
}


int N, M, K, S;
vector<pair<int, pair<int, int>>> E;
vector<int> A, B, C;

vector<int> on;
bool check() {
// cerr<<"check "<<on<<endl;
  uf.assign(N, -1);
  for (int i = 0; i < M; ++i) if (on[i]) if (A[i] != S) {
    connect(A[i], B[i]);
  }
  int cnt = 0;
  vector<int> has(N, 0);
  for (int i = 0; i < M; ++i) if (on[i]) if (A[i] == S) {
    ++cnt;
    has[root(B[i])] = 1;
  }
  if (cnt < K) return false;
  int numComps = 0;
  for (int r = 0; r < N; ++r) if (uf[r] < 0) if (r != S) {
    ++numComps;
    if (!has[r]) return false;
  }
  if (numComps > K) return false;
  return true;
}

int main() {
  for (; ~scanf("%d%d%d%d", &N, &M, &K, &S); ) {
    --S;
    E.resize(M);
    for (int i = 0; i < M; ++i) {
      int a, b, c;
      scanf("%d%d%d", &a, &b, &c);
      --a;
      --b;
      if (b == S) {
        swap(a, b);
      }
      E[i] = make_pair(c, make_pair(a, b));
    }
    sort(E.begin(), E.end());
    A.resize(M);
    B.resize(M);
    C.resize(M);
    for (int i = 0; i < M; ++i) {
      A[i] = E[i].second.first;
      B[i] = E[i].second.second;
      C[i] = E[i].first;
    }
// cerr<<"E = "<<E<<endl;
    
    /*
      - no multi-edge from S
      - not in MST other than S
    */
    vector<int> ban(M, 0);
    {
      vector<int> used(N, 0);
      for (int i = 0; i < M; ++i) if (A[i] == S) {
        if (used[B[i]]) ban[i] = 1;
        used[B[i]] = 1;
      }
    }
    {
      uf.assign(N, -1);
      for (int i = 0; i < M; ++i) if (A[i] != S) {
        if (!connect(A[i], B[i])) {
          ban[i] = 1;
        }
      }
    }
    
assert(N<=10000);
    on.resize(M);
    for (int i = 0; i < M; ++i) {
      on[i] = ban[i] ^ 1;
    }
    if (check()) {
      for (int i = M; --i >= 0; ) if (!ban[i]) {
        on[i] = 0;
        if (!check()) {
          on[i] = 1;
        }
      }
      Int ans = 0;
      for (int i = 0; i < M; ++i) if (on[i]) {
        ans += C[i];
      }
      printf("%lld\n", ans);
    } else {
      puts("nonnondayo");
    }
  }
  return 0;
}