// yukicoder: No.160 最短経路のうち辞書順最小
// 2019.7.20 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; } 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) 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 i, min;
	QUE qt;

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

//// 本問題関連
#define INF 0x33333333
#define MIN(a,b) ((a)<=(b)?(a):(b))
#define MAXV 202
int N;
int hi[MAXV], to[MAXV][MAXV], tm[MAXV][MAXV];
int vis[MAXV], prev[MAXV];

void dijkstra(int start, int goal) {
	int i, n, t;
	
	memset(vis, INF, sizeof(vis));
	memset(prev, INF, sizeof(prev));
	enq(start, 0);
	while (qsize) {
		n = que[0].n, t = que[0].t, deq();
		if (n == goal) break;
		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, enq(nx, nt);
			else if (vis[nx] == nt) prev[nx] = MIN(prev[nx], n);
		}
	}
}

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

	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(G, S);
	out(S); while (S != G) S = prev[S], pc(' '), out(S);
	pc('\n');
	return 0;
}