#include <string>
#include <vector>
#include <algorithm>
#include <numeric>
#include <set>
#include <map>
#include <queue>
#include <iostream>
#include <sstream>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstring>
#include <cctype>
#include <cassert>
#include <limits>
#include <functional>
#define rep(i,n) for(int (i)=0;(i)<(int)(n);++(i))
#define rer(i,l,u) for(int (i)=(int)(l);(i)<=(int)(u);++(i))
#define reu(i,l,u) for(int (i)=(int)(l);(i)<(int)(u);++(i))
#if defined(_MSC_VER) || __cplusplus > 199711L
#define aut(r,v) auto r = (v)
#else
#define aut(r,v) __typeof(v) r = (v)
#endif
#define each(it,o) for(aut(it, (o).begin()); it != (o).end(); ++ it)
#define all(o) (o).begin(), (o).end()
#define pb(x) push_back(x)
#define mp(x,y) make_pair((x),(y))
#define mset(m,v) memset(m,v,sizeof(m))
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3fLL
using namespace std;
typedef vector<int> vi; typedef pair<int,int> pii; typedef vector<pair<int,int> > vpii; typedef long long ll;
template<typename T, typename U> inline void amin(T &x, U y) { if(y < x) x = y; }
template<typename T, typename U> inline void amax(T &x, U y) { if(x < y) x = y; }

int main() {
	int N, M, S, G;
	scanf("%d%d%d%d", &N, &M, &S, &G);
	vector<vpii> g(N);
	rep(i, M) {
		int a, b, c;
		scanf("%d%d%d", &a, &b, &c);
		g[a].pb(mp(b, c));
		g[b].pb(mp(a, c));
	}
	rep(i, N)
		sort(all(g[i]));
	priority_queue<pii> q;
	q.push(mp(-0, G));
	vector<bool> vis(N);
	vector<int> dist(N, INF);
	while(!q.empty()) {
		int t = -q.top().first;
		int i = q.top().second;
		q.pop();
		if(vis[i]) continue;
		vis[i] = true;
		dist[i] = t;
		each(j, g[i])
			q.push(mp(-(t + j->second), j->first));
	}
	vi ans;
	int i = S;
	while(1) {
		ans.pb(i);
		if(i == G) break;
		each(j, g[i]) if(dist[j->first] + j->second == dist[i]) {
			i = j->first;
			break;
		}
	}
	rep(i, ans.size()) {
		if(i != 0) putchar(' ');
		printf("%d", ans[i]);
	}
	puts("");
	return 0;
}