#include<bits/stdc++.h>

#define vc vector
#define pb push_back
#define pf push_front
#define pii pair<int, int>
#define mkp make_pair
#define rep(i, a, b) for(int i = (a); i <= (b); ++i)
#define lep(i, a, b) for(int i = (a); i >= (b); --i)

using namespace std;

inline int read() {
	int x = 0, w = 0; char ch = getchar(); while(!isdigit(ch)) w |= (ch == '-'), ch = getchar();
	while(isdigit(ch)) x = x * 10 + (ch ^ 48), ch = getchar(); return w ? -x : x; 
}

const int N = 3e5 + 5;

int n, m, TIME, a[N], b[N], nxt[N << 1];
long long ans;

vc<int> G[N];

struct node { 
	int t; deque<pii> a; 
	inline void prework(int u, int v) {
		a.clear();
		if(!u && !v) t = 0;
		if(u && !v) t = 1, a.pb(mkp(u, u));
		if(!u && v) t = 2, a.pb(mkp(v + m, v + m));
		if(u && v) t = 3, nxt[u] = v + m, a.pb(mkp(u, v + m));
	}
} f[N];

inline void merge(int x, int y) {
	if(f[x].t == 0) return f[x] = f[y], void();
	if(f[y].t == 0) return ;
	if(f[x].t == 3 && f[y].t == 3) {
		auto [l1, r1] = f[x].a.front(); 
		auto [l2, r2] = f[y].a.front();
		nxt[r1] = l2; 
		f[x].a.pop_front(); f[x].a.pf(mkp(l1, r2));
		return ;
	}
	if(f[x].t == 3 || f[y].t == 3) {
		if(f[x].t == 3) swap(f[x], f[y]);
		if(f[x].t == 1) {
			auto [l1, r1] = f[y].a.front();
			auto [l2, r2] = f[x].a.front();
			nxt[r1] = l2; 
			f[x].a.pop_front(); f[x].a.pf(mkp(l1, r2));
		}
		else {
			auto [l1, r1] = f[x].a.back();
			auto [l2, r2] = f[y].a.front();
			nxt[r1] = l2;
			f[x].a.pop_back(); f[x].a.pb(mkp(l1, r2));
		}
		return ;
	}
	if(f[x].t != f[y].t) {
		if(f[x].t == 2) swap(f[x], f[y]);
		vc<pii> cur; int len, fl = 0;
		if(f[x].a.size() >= f[y].a.size()) {
			while(!f[y].a.empty()) {
				++TIME;
				cur.pb(f[x].a.front()); f[x].a.pop_front();
				cur.pb(f[y].a.front()); f[y].a.pop_front();
			}
			if(!f[x].a.empty()) cur.pb(f[x].a.front()), f[x].a.pop_front(), fl = 1;
			len = cur.size();
			rep(i, 0, len - 2) nxt[cur[i].second] = cur[i + 1].first;
			f[x].t = fl ? 1 : 3; f[x].a.pf(mkp(cur[0].first, cur.back().second));
		}
		else {
			while(!f[x].a.empty()) {
				++TIME;
				cur.pb(f[y].a.back()); f[y].a.pop_back();
				cur.pb(f[x].a.back()); f[x].a.pop_back();
			}
			cur.pb(f[y].a.back()); f[y].a.pop_back();
			reverse(cur.begin(), cur.end());
			len = cur.size();
			rep(i, 0, len - 2) nxt[cur[i].second] = cur[i + 1].first;
			f[x] = f[y]; f[x].a.pb(mkp(cur[0].first, cur.back().second));
		}
	}
	else {
		if(f[x].a.size() < f[y].a.size()) swap(f[x], f[y]);
		while(!f[y].a.empty()) ++TIME, f[x].a.pb(f[y].a.front()), f[y].a.pop_front();
	}
}

inline void dfs1(int x, int fa) {
	f[x].prework(a[x], b[x]);
	for(auto y : G[x]) if(y != fa) 
		dfs1(y, x), merge(x, y), f[y].a.shrink_to_fit();
}

inline void dfs2(int x, int fa) {
	a[x] = a[x] > 0; b[x] = b[x] > 0;
	for(auto y : G[x]) if(y != fa) {
		dfs2(y, x); a[x] += a[y]; b[x] += b[y];
		if(a[y] || b[y]) ans += 2 * max(1, abs(a[y] - b[y]));
	}
}

signed main() {
	n = read(); m = read();
	rep(i, 1, m) a[read()] = i;
	rep(i, 1, m) b[read()] = i;
	for(int i = 1, u, v; i < n; i++) 
		u = read(), v = read(), G[u].pb(v), G[v].pb(u);
	
	dfs1(1, 0);
	dfs2(1, 0);
	
	cout << ans << endl;
	for(int x = f[1].a.front().first; x; x = nxt[x]) printf("%d ", x <= m ? x : x - m);
	putchar(10);
	return 0;
}