// yukicoder: No.160 最短経路のうち辞書順最小
// 2019.7.19 bal4u

#include <stdio.h>
#include <string.h>

#if 1
#define gc() getchar_unlocked()
#define pc(c) putchar_unlocked(c)
#else
#define gc() getchar()
#define pc(c) putchar(c)
#endif

int in() {   // 非負整数の入力
	int n = 0, c = gc();
	do n = 10 * n + (c & 0xf); while ((c = gc()) >= '0');
	return n;
}

void out(int n) { // 非負整数の表示（出力）
	int i;
	char b[20];

	if (!n) pc('0');
	else {
		i = 0; while (n) b[i++] = n % 10 + '0', n /= 10;
		while (i--) pc(b[i]);
	}
}

//// 優先度付きキュー（ダイクストラ法用）
#define MAX 1000000
typedef struct { int t, n, pre; } QUE;
QUE que[MAX]; int qsize;

#define PARENT(i) ((i)>>1)
#define LEFT(i)   ((i)<<1)
#define RIGHT(i)  (((i)<<1)+1)

void min_heapify(int i) {
	int l, r, min;
	QUE qt;

	l = LEFT(i), r = RIGHT(i);
	if (l < qsize && (que[l].t < que[i].t ||
		(que[l].t == que[i].t && que[l].pre < que[i].pre))) min = l; else min = i;
	if (r < qsize && que[r].t < que[min].t) min = r;
	if (min != i) {
		qt = que[i]; que[i] = que[min]; que[min] = qt;
		min_heapify(min);
	}
}

void deq() {
	que[0] = que[--qsize];
	min_heapify(0);
}

void enq(int n, int t, int pre) {
	int i, min;
	QUE qt;

	i = qsize++;
	que[i].t = t, que[i].n = n, que[i].pre = pre;
	while (i > 0 && (que[min = PARENT(i)].t > que[i].t
		|| (que[min].t == que[i].t && que[min].pre > que[i].pre))) {
		qt = que[i]; que[i] = que[min]; que[min] = qt;
		i = min;
	}
}

//// 本問題関連
#define INF 0x33333333
#define MAXV 202
int N, S, G;
int hi[MAXV], to[MAXV][MAXV], tm[MAXV][MAXV];
int vis[MAXV];
int prev[MAXV];
int a[MAXV], sz;

int path(int *a, int n, int pre) {
	int i, w = 0;
	a[w++] = n, n = pre;
	while (n >= 0) a[w++] = n, n = prev[n];
	a[w] = -1;
	return w;
}

void dijkstra() {
	int i, n, t, pre, mi;
	int tmp[MAXV], tsz;
	
	mi = INF, memset(vis, INF, sizeof(vis));
	enq(G, 0, -1);
	while (qsize) {
		n = que[0].n, t = que[0].t, pre = que[0].pre, deq();
		if (n == S) {
			if (t > mi) return;
			if (t < mi) sz = path(a, n, pre), mi = t;
			else {
				tsz = path(tmp, n, pre);
				for (i = 0; a[i] == tmp[i]; i++);
				if (tmp[i] < a[i]) {
					for (i = 0; i < tsz; i++) a[i] = tmp[i]; 
					sz = tsz;
				}
			}
			continue;
		}
		if (vis[n] < t || (vis[n] == t && prev[n] <= pre)) continue;
		vis[n] = t, prev[n] = pre;
		for (i = 0; i < hi[n]; i++) {
			int nx = to[n][i], nt = t+tm[n][i];
			if (vis[nx] < nt || (vis[nx] == nt && prev[nx] <= n)) continue;
			enq(nx, nt, n);
		}
	}
}

int main()
{
	int i, k, M;

	N = in(), M = in(), S = in(), G = in();
	while (M--) {
		int a = in(), b = in(), c = in();
		k = hi[a]++, to[a][k] = b, tm[a][k] = c;
		k = hi[b]++, to[b][k] = a, tm[b][k] = c;
	}
	dijkstra();
	out(a[0]); for (i = 1; i < sz; i++) pc(' '), out(a[i]);	pc('\n');
	return 0;
}