// 基本テンプレート (縮小版)

#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,n) for(int (i)=(a); (i)<(n); (i)++)
#define repq(i,a,n) for(int (i)=(a); (i)<=(n); (i)++)
#define repr(i,a,n) for(int (i)=(a); (i)>=(n); (i)--)
#define int long long
template<typename T> void chmax(T &a, T b) {a = max(a, b);}
template<typename T> void chmin(T &a, T b) {a = min(a, b);}
template<typename T> void chadd(T &a, T b) {a = a + b;}
typedef pair<int, int> pii;
typedef long long ll;
constexpr ll INF = 1001001001001001LL;
constexpr ll MOD = 1000000007LL;

int N, M, S, G;
int dist[210];
int E[210][210];

signed main() {
    memset(E, -1, sizeof(E));
    cin >> N >> M >> S >> G;
    rep(i,0,M) {
        int a, b, c; cin >> a >> b >> c;
        E[a][b] = c;
        E[b][a] = c;
    }
    fill(dist, dist+N, INF);
    dist[G] = 0;

    priority_queue< pii, vector<pii>, greater<pii> > q;
    q.push( pii(0, G) );
    while(!q.empty()) {
        pii cur = q.top(); q.pop();
        int d = cur.first, pt = cur.second;
        repr(i,N-1,0) {
            if(i == pt || E[i][pt] < 0) continue;
            if(dist[i] > dist[pt] + E[i][pt]) {
                dist[i] = dist[pt] + E[i][pt];
                q.push( pii(dist[i], i) );
            }
        }
    }

    vector<int> ans;
    int pt = S;
    ans.push_back(pt);
    while(pt != G) {
        rep(i,0,N) {
            if(E[pt][i] < 0 || i == pt) continue;
            if(dist[pt] - dist[i] == E[pt][i]) {
                pt = i;
                ans.push_back(pt);
                break;
            }
        }
    }
    rep(i,0,ans.size()) cout << (i==0 ? "" : " ") << ans[i];
    cout << endl;
    return 0;
}