#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=int(a);i<int(b);++i)
using namespace std;
typedef long long ll;
typedef pair<int,string> P;
int INF = (1LL << 30) - 1;
int MOD = 1e9+7;
int N,M,S,G;
int dest[200][200];
int used[200];
stack<int> st;
bool dfs(int now, int res){
    if(now == G && res == 0){
        st.push(now);
        return true;
    }
    rep(i,0,N){
        if(i == now || used[i] || res < dest[now][i])continue;
        used[i] = 1;
        if(dfs(i, res - dest[now][i])){
            st.push(now);
            return true;
        }
        used[i] = 0;
    }
    return false;
}
main(){
    cin >> N >> M >> S >> G;
    P dist[N][N];
    rep(i,0,N)rep(j,0,N){
        dest[i][j] = INF;
        dist[i][j] = P(INF, {i, j});
    }
    //rep(i,0,N)dist[i][i].first = 0;
    int A[M],B[M],C[M];
    rep(i,0,M){
        cin >> A[i] >> B[i] >> C[i];
        dest[A[i]][B[i]] = dest[B[i]][A[i]] = C[i];
        dist[A[i]][B[i]].first = dist[B[i]][A[i]].first = C[i];
    }
    
    rep(i,0,N)rep(j,0,N)rep(k,0,N){
        string str = dist[j][i].second + dist[i][k].second.substr(1);
        //string str = dist[j][i].second + dist[i][k].second;
        if(dist[j][k].first > dist[j][i].first + dist[i][k].first ||
        dist[j][k].first == dist[j][i].first + dist[i][k].first &&
        dist[j][k].second > str){
            dist[j][k].first = dist[j][i].first + dist[i][k].first;
            dist[j][k].second = str;
        }
    }
    //cout << dist[S][G].second << endl;
    for(auto c:dist[S][G].second){
        cout << (((int)c) + 256 )% 256 << " ";
    }
    cout << endl;
}