#include using namespace std; typedef long long signed int LL; typedef long long unsigned int LU; #define incID(i, l, r) for(int i = (l) ; i < (r); i++) #define incII(i, l, r) for(int i = (l) ; i <= (r); i++) #define decID(i, l, r) for(int i = (r) - 1; i >= (l); i--) #define decII(i, l, r) for(int i = (r) ; i >= (l); i--) #define inc(i, n) incID(i, 0, n) #define inc1(i, n) incII(i, 1, n) #define dec(i, n) decID(i, 0, n) #define dec1(i, n) decII(i, 1, n) #define inII(v, l, r) ((l) <= (v) && (v) <= (r)) #define inID(v, l, r) ((l) <= (v) && (v) < (r)) #define PB push_back #define EB emplace_back #define MP make_pair #define FI first #define SE second #define UB upper_bound #define LB lower_bound #define PQ priority_queue #define ALL(v) v.begin(), v.end() #define RALL(v) v.rbegin(), v.rend() #define FOR(it, v) for(auto it = v.begin(); it != v.end(); ++it) #define RFOR(it, v) for(auto it = v.rbegin(); it != v.rend(); ++it) template bool setmin(T & a, T b) { if(b < a) { a = b; return true; } else { return false; } } template bool setmax(T & a, T b) { if(b > a) { a = b; return true; } else { return false; } } template bool setmineq(T & a, T b) { if(b <= a) { a = b; return true; } else { return false; } } template bool setmaxeq(T & a, T b) { if(b >= a) { a = b; return true; } else { return false; } } template T gcd(T a, T b) { return (b == 0 ? a : gcd(b, a % b)); } template T lcm(T a, T b) { return a / gcd(a, b) * b; } // ---- ---- template class RPQ : public PQ, greater> { }; template void dijkstra(int start, vector> g[], Cost dist[]) { RPQ> q; dist[start] = 0; q.emplace(dist[start], start); while(! q.empty()) { auto cp = q.top(); q.pop(); int p = cp.SE; Cost c = cp.FI; if(dist[p] != c) { continue; } for(auto && e : g[p]) { int ep = e.FI; Cost ec = e.SE; if(setmin(dist[ep], dist[p] + ec)) { q.emplace(dist[ep], ep); } } } return; } int n, m, s, g; vector> v[200]; int d[200], INF = 3000000; vector ans; bool memo[200]; bool dfs(int p) { if(memo[p]) { return false; } ans.PB(p); if(p == g) { return true; } inc(i, v[p].size()) { if(d[p] + v[p][i].SE == d[v[p][i].FI] && dfs(v[p][i].FI)) { return true; } } ans.pop_back(); memo[p] = true; return false; } int main() { cin >> n >> m >> s >> g; inc(i, m) { int a, b, c; cin >> a >> b >> c; v[a].EB(b, c); v[b].EB(a, c); } inc(i, n) { d[i] = INF; } dijkstra(s, v, d); inc(i, n) { sort(ALL(v[i])); } dfs(s); inc(i, ans.size()) { cout << (i == 0 ? "" : " ") << ans[i]; } cout << endl; return 0; }