#include<bits/stdc++.h>
#define ll long long
using namespace std;

const int maxn = 210000;

int n,m;
vector<int>V[maxn];
int o[maxn];

int ans;
void dfs(const int x,const int fa,int c)
{
	int s=0;
	for(auto y:V[x]) if(y!=fa)
	{
		s+= o[y]==0;
	}
	if(c+o[x]==0) ans++;
	else if(c+o[x]==1)
	{
		if(s>=1) c=1,ans++;
		else return;
	}
	else return;
	
	for(auto y:V[x]) if(y!=fa)
	{
		if(o[y]==0)
			dfs(y,x,s>1?0:c);
		else
			dfs(y,x,s>0?0:c);
	}
}

int main()
{
	ios_base::sync_with_stdio(false);
	
	cin>>n>>m;
	for(int i=1;i<n;i++)
	{
		int x,y; cin>>x>>y;
		V[x].push_back(y);
		V[y].push_back(x);
	}
	for(int i=1;i<=m;i++)
	{
		int x; cin>>x;
		o[x]=1;
	}
	
	dfs(1,0,0);
	
	cout<<ans<<endl;
	
	return 0;
}