import core.thread;
import std.conv, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.container, std.math, std.range, std.regex;

//	Input
class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { tokens = readln.split; if (tokens.empty && stdin.eof) throw new EOFException; } auto token = tokens[0]; tokens.popFront; return token; }
int readInt() { return to!int(readToken); }
long readLong() { return to!long(readToken); }
real readReal() { return to!real(readToken); }

//	chmin/chmax
void chmin(T)(ref T t, in T f) { if (t > f) t = f; }
void chmax(T)(ref T t, in T f) { if (t < f) t = f; }

//	Pair
struct Pair(S, T) {
	S x; T y;
	int opCmp(    const Pair p) const { return (x < p.x) ? -1 : (x > p.x) ? +1 : (y < p.y) ? -1 : (y > p.y) ? +1 : 0; }
	int opCmp(ref const Pair p) const { return (x < p.x) ? -1 : (x > p.x) ? +1 : (y < p.y) ? -1 : (y > p.y) ? +1 : 0; }
	string toString() const { return "(" ~ to!string(x) ~ ", " ~ to!string(y) ~ ")"; }
}
auto pair(S, T)(inout(S) x, inout(T) y) { return Pair!(S, T)(x, y); }

//	Array
int binarySearch(T)(in T[] as, in bool delegate(T) test) { int low = -1, upp = as.length; for (; low + 1 < upp; ) { int mid = (low + upp) >> 1; (test(as[mid]) ? low : upp) = mid; } return upp; }
int lowerBound(T)(in T[] as, in T val) { return as.binarySearch((T a) { return (a <  val); }); }
int upperBound(T)(in T[] as, in T val) { return as.binarySearch((T a) { return (a <= val); }); }
T[] unique(T)(in T[] as) { T[] bs; foreach (a; as) if (bs.empty || bs[$ - 1] != a) bs ~= a; return bs; }


immutable INF = 10^^9;

int N, M, S, T;
int[][] C, D;

void main(string[] args) {
	try {
	for (; ; ) {
		N = readInt;
		M = readInt;
		S = readInt;
		T = readInt;
		C = new int[][](N, N);
		D = new int[][](N, N);
		foreach (u; 0 .. N) {
			C[u][] = INF;
			C[u][u] = 0;
			D[u][] = INF;
			D[u][u] = 0;
		}
		foreach (i; 0 .. M) {
			const u = readInt;
			const v = readInt;
			const c = readInt;
			chmin(C[u][v], c);
			chmin(C[v][u], c);
			chmin(D[u][v], c);
			chmin(D[v][u], c);
		}
		
		foreach (w; 0 .. N) foreach (u; 0 .. N) foreach (v; 0 .. N) {
			chmin(D[u][v], D[u][w] + D[w][v]);
		}
		int[] us;
		for (int u = S; ; ) {
			us ~= u;
			if (u == T) {
				break;
			}
			bool ok;
			foreach (v; 0 .. N) {
				if (u != v && D[u][T] == C[u][v] + D[v][T]) {
					ok = true;
					u = v;
					break;
				}
			}
			assert(ok);
		}
		writeln(us.to!string.removechars("[],"));
		
	}
	} catch (EOFException) {}
}