#include<stdio.h>
#include<vector>
#include<list>
#define N 300009
using namespace std;
inline char nc()
{
	static char buf[99999],*l,*r;
	return l==r&&(r=(l=buf)+fread(buf,1,99999,stdin),l==r)?EOF:*l++;
}
inline void read(int&x)
{
	char c=nc();for(;c<'0'||'9'<c;c=nc());
	for(x=0;'0'<=c&&c<='9';x=(x<<3)+(x<<1)+(c^48),c=nc());
}
int n,m,a[N],b[N],ca[N],cb[N],h[N],e[N<<1],nxt[N<<1];long long ans;
vector<list<int> >x[N];
inline void onion(list<int>&u,list<int>&v){u.splice(u.end(),v);}
inline void onion(vector<list<int> >&u,vector<list<int> >&v)
{
	if(u.size()<v.size())u.swap(v);
	for(;v.size();u.emplace_back(),onion(u.back(),v.back()),v.pop_back());
}
inline void dfs(int i,int f)
{
	for(int j=h[i];j;j=nxt[j])if(e[j]^f)
	{
		dfs(e[j],i);
		ca[i]+=ca[e[j]];cb[i]+=cb[e[j]];
	}
	if(!ca[i])if(!cb[i])return;
	if(ca[i]==cb[i])ans+=!!i<<1;
	else ans+=(ca[i]<cb[i]?cb[i]-ca[i]:ca[i]-cb[i])<<1;
	vector<list<int> >u,v;list<int>w;
	if(a[i])
		if(b[i])w.emplace_back(a[i]),w.emplace_back(b[i]);
		else u.emplace_back(list<int>{a[i]});
	else if(b[i])v.emplace_back(list<int>{b[i]});
	for(int j=h[i];j;j=nxt[j])if(e[j]^f)
		if(ca[e[j]]<cb[e[j]])onion(v,x[e[j]]);
		else if(ca[e[j]]>cb[e[j]])onion(u,x[e[j]]);
		else if(x[e[j]].size())onion(w,x[e[j]][0]);
	for(;u.size()>1&&v.size();onion(u[u.size()-2],v.back()),onion(u[u.size()-2],
		u.back()),u.pop_back(),v.pop_back());
	for(;v.size()>1&&u.size();onion(v[v.size()-2],u.back()),onion(v[v.size()-2],
		v.back()),u.pop_back(),v.pop_back());
	if(ca[i]>cb[i])
	{
		if(w.size())onion(w,u.back()),u.back().swap(w);
		x[i].swap(u);
	}
	else if(ca[i]<cb[i])
	{
		if(w.size())onion(v.back(),w);
		x[i].swap(v);
	}
	else
	{
		if(u.size())onion(w,u.back());
		if(v.size())onion(w,v.back());
		x[i].emplace_back();x[i][0].swap(w);
	}
}
main()
{
	read(n);read(m);
	for(int i=1,x;i<=m;read(x),--x,a[x]=i,ca[x]=1,++i);
	for(int i=1,x;i<=m;read(x),--x,b[x]=i,cb[x]=1,++i);
	for(int i=1,u,v;i<n;++i)read(u),read(v),--u,--v,
		e[i]=v,nxt[i]=h[u],h[u]=i,e[i+n]=u,nxt[i+n]=h[v],h[v]=i+n;
	dfs(0,0);
	printf("%lld\n",ans);
	for(int i:x[0][0])printf("%d ",i);
}