#include <bits/stdc++.h>
using namespace std;
//#define int long long
typedef long long ll;
const int N=114514,p1=1000000007,p2=1145141923,Inf=0x3f3f3f3f;
struct Xds{
	int ls=0,rs=0,l=0,r=0,v=0,hs1=0,hs2=0,tag=-1;
}a[N<<6];
int pw1[N],pw2[N];
int new_Xds(){static int p=0;return ++p;}
int new_Xds(int i){int p=new_Xds();a[p]=a[i];return p;}
void new_so(int i){a[i].ls=new_Xds(a[i].ls);a[i].rs=new_Xds(a[i].rs);}
void push_down(int i,int j){
	if(a[i].tag!=-1){
		a[j].v=a[i].tag?(a[j].r-a[j].l+1):0;
		a[j].hs1=a[i].tag?(pw1[a[j].r-a[j].l+1]-1):0;
		a[j].hs2=a[i].tag?(pw2[a[j].r-a[j].l+1]-1):0;
		a[j].tag=a[i].tag;
	}
}
void push_down(int i){
	new_so(i);
	push_down(i,a[i].ls);
	push_down(i,a[i].rs);
	a[i].tag=-1;
}
void push_up(int i){
	a[i].v=a[a[i].ls].v+a[a[i].rs].v;
	a[i].hs1=((ll)a[a[i].ls].hs1+(ll)a[a[i].rs].hs1*(ll)pw1[a[a[i].ls].r-a[a[i].ls].l+1])%p1;
	a[i].hs2=((ll)a[a[i].ls].hs2+(ll)a[a[i].rs].hs2*(ll)pw2[a[a[i].ls].r-a[a[i].ls].l+1])%p2;
}
void build(int i,int l,int r){
	a[i].l=l;
	a[i].r=r;
	if(a[i].l==a[i].r){return;}
	new_so(i);
	int mid=a[i].l+a[i].r>>1;
	build(a[i].ls,l,mid);
	build(a[i].rs,mid+1,r);
}
int build(){int rt=new_Xds();build(rt,1,N);return rt;}
int cmp_(int i1,int i2){
	if(a[i1].hs1==a[i2].hs1 && a[i1].hs2==a[i2].hs2) return 0;
	if(a[i1].l==a[i1].r){
		return a[i1].v<a[i2].v?-1:(a[i1].v==a[i2].v?0:1);
	}
	push_down(i1);
	push_down(i2);
	if(a[a[i1].rs].hs1!=a[a[i2].rs].hs1 || a[a[i1].rs].hs2!=a[a[i2].rs].hs2){
		return cmp_(a[i1].rs,a[i2].rs);
	}
	else{
		return cmp_(a[i1].ls,a[i2].ls);
	}
}
bool cmp(int& rt1,int& rt2){int p1=new_Xds(rt1),p2=new_Xds(rt2);bool b=cmp_(p1,p2);rt1=p1,rt2=p2;return b;}
void change_(int i,int l,int r,int x){
	if(a[i].l>=l && a[i].r<=r){
		a[i].v=x?(a[i].r-a[i].l+1):0;
		a[i].hs1=x?(pw1[a[i].r-a[i].l+1]-1):0;
		a[i].hs2=x?(pw2[a[i].r-a[i].l+1]-1):0;
		a[i].tag=x;
//		cout << a[i].l << " " << a[i].r << " " << a[i].v << " " << a[i].hs1 << " " << a[i].hs2 << " " << a[i].tag << endl;
		return;
	}
	push_down(i);
	int mid=a[i].l+a[i].r>>1;
	if(mid>=l) change_(a[i].ls,l,r,x);
	if(mid<r) change_(a[i].rs,l,r,x);
	push_up(i);
}
int change(int rt,int l,int r,int x){int p=new_Xds(rt);change_(p,l,r,x);return p;}
int query_(int i,int l,int r){
	if(a[i].l>=l && a[i].r<=r) return a[i].v;
	push_down(i);
	int mid=a[i].l+a[i].r>>1,ans=0;
	if(mid>=l) ans+=query_(a[i].ls,l,r);
	if(mid<r) ans+=query_(a[i].rs,l,r);
	return ans;
}
int query(int& rt,int l,int r){int p=new_Xds(rt);int ans=query_(p,l,r);rt=p;return ans;}
int add(int rt,int x){
	int p=new_Xds(rt);
	int l=x-1,r=N-2;
	while(l<r){
		int mid=l+r+1>>1;
		if(query(p,x,mid)==mid-x+1) l=mid;
		else r=mid-1;
	}
	if(l>=x) p=change(p,x,l,0);
	p=change(p,l+1,l+1,1);
	return p;
}
int n,m,bg,ed;
struct Edge{
	int v,w;
	Edge(){}
	Edge(int v_,int w_):v(v_),w(w_){}
};
vector<Edge> G[N];
struct qwq{
	int u,lt,ds;
	qwq(){}
	qwq(int u_,int lt_,int ds_):u(u_),lt(lt_),ds(ds_){}
};
struct my_cmp{
	bool operator ()(qwq x,qwq y){
		return cmp(x.ds,y.ds)==1;
	}
};
priority_queue<qwq,vector<qwq>,my_cmp> q;
int dis[N],lt[N];
void dijkstra(int u){
	q.push(qwq(u,0,build()));
	while(!q.empty()){
		qwq u=q.top();
//		cout << u.u << " " << u.ds << " " << a[u.ds].hs1 << endl;
		q.pop();
		if(dis[u.u]) continue;
		dis[u.u]=u.ds;
		lt[u.u]=u.lt;
		for(Edge v:G[u.u]) q.push(qwq(v.v,u.u,add(u.ds,v.w)));
	}
}
vector<int> ans;
signed main(){
	pw1[0]=pw2[0]=1;
	for(int i=1;i<N;++i) pw1[i]=pw1[i-1]*2%p1,pw2[i]=pw2[i-1]*2%p2;
	cin >> n >> m;
	while(m--){
		int u,v,w;
		cin >> u >> v >> w;
		G[u].push_back(Edge(v,w+1));
		G[v].push_back(Edge(u,w+1));
	}
	cin >> bg >> ed;
	dijkstra(bg);
//	for(int i=1;i<=n;++i) cout << a[dis[i]].hs1 << endl;
	if(bg==ed){
		cout << "0\n1\n" << bg << endl;
		return 0;
	}
	if(a[dis[ed]].hs1==0 && a[dis[ed]].hs2==0){
		cout << "-1" << endl;
		return 0;
	}
	cout << a[dis[ed]].hs1 << endl;
	while(ed!=0) ans.push_back(ed),ed=lt[ed];
	cout << ans.size() << endl;
	for(int i=ans.size()-1;i>=0;--i) cout << ans[i] << " ";
	return 0;
}