#include <bits/stdc++.h>
using namespace std;
#define ll long long
const int N=3e5+7;
const ll inf=0x3f3f3f3f3f3f3f3f;
int n,m,s,cnt;
ll dis[N];
bool vis[N];
struct edge{
	int next;
	int to;
	ll w;
}edge[N<<1];
int h[N];
struct Node{
	int id;
	ll dis;
}node[N<<1];
bool operator<(Node a,Node b){
	return a.dis>b.dis;
}
priority_queue<Node>q;
int pre[N];
ll tot,t;
ll b[N];
void add(int u,int v,ll w){
	edge[++cnt]={h[u],v,w},h[u]=cnt;
	return;
}
void dijk(int s){
	dis[s]=0;
	q.push({s,0});
	while(q.size()){
		int u=q.top().id;q.pop();
		if(vis[u])continue;
		vis[u]=1;
		for(int i=h[u];~i;i=edge[i].next){
			int v=edge[i].to;
			ll w=edge[i].w;
			if(dis[u]+w<dis[v]){
				dis[v]=dis[u]+w;
				pre[v]=i;
				q.push({v,dis[v]});
			}
			if(dis[u]+w==dis[v]){
				if(w<edge[pre[v]].w){
					pre[v]=i;
				}
			}
		}
	}
	return;
}
int main(){
	memset(h,-1,sizeof(h));
	memset(dis,0x3f,sizeof(dis));
	memset(vis,0,sizeof(vis));
	memset(pre,0,sizeof(pre));
	scanf("%d%d",&n,&m);
	for(int i=1;i<=m;i++){
		int x,y;
		ll z;
		scanf("%d%d%d",&x,&y,&z);
		add(x,y,z);
		add(y,x,z);
	}
	scanf("%d",&s);
	dijk(s);
	for(int i=1;i<=n;i++){
		if(i==s)continue;
		tot+=edge[pre[i]].w;
		b[++t]=pre[i];
	}
	sort(b+1,b+t+1);
	printf("%d\n",tot);
	for(int i=1;i<=t;i++){
		printf("%d ",(b[i]+1)/2);
	}
	puts("");
	return 0;
}

调了一个多小时了...