#include<stdio.h>
#include<stdlib.h>

#define POS(i,j) ((i)*n+(j))

void run(void){
  int n,m,src,dst;
  scanf("%d%d%d%d",&n,&m,&src,&dst);
  int *g=(int *)calloc(n*n,sizeof(int));
  while(m--){
    int a,b,c;
    scanf("%d%d%d",&a,&b,&c);
    g[POS(a,b)]=c;
    g[POS(b,a)]=c;
  }
  int *dp=(int *)calloc(n,sizeof(int));
  const int inf=10000*n+1;
  int i,j;
  for(i=0;i<n;i++) dp[i]=inf;
  dp[src]=0;
  int *used=(int *)calloc(n,sizeof(int));
  for(i=0;i<n;i++){
    for(j=0;used[j];j++);
    int v=j;
    for(;j<n;j++){
      if(!used[j] && dp[j]<dp[v]){
	v=j;
      }
    }
    used[v]=1;
    for(j=0;j<n;j++){
      if(g[POS(v,j)]==0 || dp[j]<=dp[v]+g[POS(v,j)]) continue;
      dp[j]=dp[v]+g[POS(v,j)];
    }
  }
  int *can=(int *)calloc(n,sizeof(int));
  can[dst]=1;
  for(i=0;i<n;i++){
    for(j=0;j<n && can[j]!=1;j++);
    if(j>=n) break;
    int v=j;
    can[v]=2;
    for(j=0;j<n;j++){
      if(can[j]!=0) continue;
      if(g[POS(j,v)]==0) continue;
      if(dp[v]<dp[j]+g[POS(j,v)]) continue;
      can[j]=1;
    }
  }
  int now=src;
  while(now!=dst){
    printf("%d ",now);
    for(j=0;j<n;j++){
      if(can[j] && g[POS(now,j)]>0 && dp[j]==dp[now]+g[POS(now,j)]){
	break;
      }
    }
    now=j;
  }
  printf("%d\n",now);
  return;
}

int main(void){
  run();
  return 0;
}