B

#include <algorithm>
#include <cassert>
#include <cstdio>
#include <iostream>
#include <set>
#include <vector>

using namespace std;

const int N = 50;

vector<pair<int, int>> a[N];

int d[2019][N];

const int oo = 50 * 2019 * 1000;

int n, m, s, t;

set<pair<int, pair<int, int>>> pending;

void update(int remainder, int vertex, int distance) {
  if (d[remainder][vertex] > distance) {
    d[remainder][vertex] = distance;
    pending.insert(make_pair(distance, make_pair(remainder, vertex)));
  }
}

pair<int, int> pop() {
  auto x = *pending.begin();
  pending.erase(pending.begin());
  return x.second;
}

int main() {
  cin >> n >> m >> s >> t;
  assert(0 < n && n <= 50);
  assert(0 <= m && m <= 2000);
  assert(0 < s && s <= n);
  assert(0 < t && t <= n);
  s--;
  t--;
  for (int i = 0; i < m; i++) {
    int x, y, l;
    cin >> x >> y >> l;
    assert(0 < x && x <= n);
    assert(0 < y && y <= n);
    assert(0 < l && l <= 1000);
    x--;
    y--;
    a[x].push_back(make_pair(y, l));
    a[y].push_back(make_pair(x, l));
  }

  for (int i = 0; i < 2019; i++)
    for (int j = 0; j < n; j++) {
      d[i][j] = oo;
    }
  update(1, s, 0);
  while (!pending.empty()) {
    auto cur = pop();
    int remx = cur.first;
    int remy = (remx + 1) % 2019;
    int x = cur.second;
    int dx = d[remx][x];
    for (auto yl : a[x]) {
      update(remy, yl.first, dx + yl.second);
    }
  }
  if (d[0][t] == oo) {
    cout << "Mumkun emes" << endl;
  } else {
    cout << d[0][t] << endl;
  }
  return 0;
}