#pragma GCC optimizer("Ofast")
#pragma GCC target("avx2")
#include <bits/stdc++.h>
#define int long long 
#define ld long double
#define ull unsigned long long 
#define fr first
#define fi first
#define sc second
#define se second
#define all(x) x.begin(), x.end()
#define pii pair<int,int>
using namespace std;

#ifndef fireball
#define tofu ios::sync_with_stdio(0); cin.tie(0);
#else
#define tofu freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout);
#endif 

void db() {cout << '\n';}
template <typename T, typename ...U> void db(T a, U ...b) {cout << a << ' ', db(b...);}

signed main(){
    tofu;

    int n, m;
    cin >> n >> m;
    vector<int> g[n + 1];
    for(int i = 1; i < n; ++i){
        int x, y;
        cin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    int a[n + 1] = {};
    for(int i = 0; i < m; ++i){
        int x; cin >> x;
        a[x] = 1;
    }

    int vis[n + 1] = {};
    function<void(int,int, int)> dfs = [&](int u, int pa, int f){
        vis[pa] = 1;
        if(g[u].size() == 1){
            if(f == 0) vis[u] = 1;
            return;
        }

        int has = 0;
        for(int i : g[u]) if(i != pa and !a[i]) has++;
        for(int i : g[u]){
            if(i == pa) continue;
            if(a[i]){
                if(f == 0) dfs(i, u, 1);
                else if(has) dfs(i, u, 1);
            }
            else{
                if(has > 1) dfs(i, u, 0);
                else dfs(i, u, f);
            }
        }
    };

    for(int i : g[1]){
        if(a[i]) dfs(i, 1, 1);
        else dfs(i, 1, 0);
    }

    //for(int i = 1; i <= n; ++i) db(i, vis[i]);

    int ans = 0;
    for(int i = 1; i <= n; ++i) ans += vis[i];
    db(ans);
}