#include <bits/stdc++.h> #define f first #define se second using namespace std; vector<pair<int, int>> ad[107]; int d[107]; int bac[107]; void dikstra(int z) { queue<int> q; q.push(z); d[z] = bac[z] = 0; while (!q.empty()) { int u = q.front(); q.pop(); for (pair<int, int> x : ad[u]) { if (d[u] + x.se < d[x.f]) { d[x.f] = d[u] + x.se; bac[x.f] = u; q.push(x.f); } } } } int main() { fill(d + 1, d + 107, 10000); int n, m, s, t; cin >> n >> m >> s >> t; for (int i = 1; i <= m; i++) { int x, y, z; cin >> x >> y >> z; ad[x].push_back({ y, z }); ad[y].push_back({ x, z }); } dikstra(s); if (d[t] == 10000) cout << 0 << '\n'; else { cout << d[t] << '\n'; vector<int> stor; while (t > 0) { stor.push_back(t); t = bac[t]; } reverse(stor.begin(), stor.end()); for (int tp : stor) cout << tp << ' '; } return 0; }