# include <bits/stdc++.h>
using namespace std;
int rt=0,ans=0,cnt[500010],cnt2[500010],cnt3[500010],dep[500010],dfn[500010],in[500010],minn[1000010][20],tot=0,tot2=0;
vector<int> G[500010],vec[500010];
inline int getmin(int x,int y){return dep[x]<dep[y]?x:y;}
void dfs1(int u,int fa)
{
	dfn[u]=++tot;
	minn[in[u]=++tot2][0]=u;
	for(int v:G[u])
	{
		if(v==fa) continue;
		dep[v]=dep[u]+1;
		dfs1(v,u);
		minn[++tot2][0]=u;
	}
}
void dfs2(int u,int fa)
{
	for(int v:G[u])
	{
		if(v==fa) continue;
		dfs2(v,u);
		if(!cnt[v] && (!rt || dep[u]<dep[rt])) rt=u;
		cnt[u]+=cnt[v];
		cnt2[u]+=cnt2[v]+(!cnt[v]);
		cnt3[u]+=(cnt2[v]+(!cnt[v])>0);
		ans+=(!cnt[v] && !cnt2[v]);
	}
}
int Lca(int u,int v)
{
	u=in[u];v=in[v];
	if(u>v) swap(u,v);
	int k=__lg(v-u+1);
	return getmin(minn[u][k],minn[v-(1<<k)+1][k]);
}
int main()
{
	int n,m,u,v;
	cin>>n>>m;
	for(int i=1;i<n;i++)
	{
		scanf("%d%d",&u,&v);
		G[u].push_back(v);
		G[v].push_back(u);
	}
	dfs1(1,0);
	for(int i=tot2;i;i--)
		for(int j=1;i+(1<<j)<=tot2;j++)
			minn[i][j]=getmin(minn[i][j-1],minn[i+(1<<j-1)][j-1]);
	for(int i=1;i<=n;i++) scanf("%d",&u),vec[u].push_back(i);
	for(int i=1;i<=m;i++)
	{
		int le=0,ri=0;
		for(int u:vec[i])
		{
			cnt[u]++;
			if(!le || dfn[u]<dfn[le]) le=u;
			if(!ri || dfn[u]>dfn[ri]) ri=u;
		}
		cnt[Lca(le,ri)]-=vec[i].size();
	}
	dfs2(1,0);
	ans=(ans+(cnt3[rt]==1)+1)/2;
	cout<<ans<<endl;
	return 0;
}