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

#ifdef DEBUG
#define fast
#else
#define fast cin.tie(0)->sync_with_stdio(0)
#define cerr if(1);else cerr
#define endl '\n'
#endif
#define _ <<' '<<
#define ALL(v) v.begin(),v.end()
#define ft first
#define sd second

using ll = long long;
using ld = long double;
using pii = pair<int,int>;

const int maxn = 2e5+50;
vector<int> G[maxn];
int has[maxn];

int ans = 0;

void dfs(int cur, int fa, bool gg) {
    if (has[cur] && gg) return;

    cerr _ "dfs" _ cur _ fa _ gg _ endl;

    int can = 0;
    for (int &nxt : G[cur]) {
        if (nxt == fa) continue;
        can += !has[nxt];
    }

    gg |= has[cur];

    if (can || !gg) {
        cerr << "can : " << cur << endl;
        ++ans;
    }
    
    for (int &nxt : G[cur]) {
        if (nxt != fa) {
            if ((can - !has[nxt])) dfs(nxt, cur, 0);
            else dfs(nxt, cur, gg);
        }
    }
}


signed main() {
    fast;

    int n, k;
    cin >> n >> k;
    for (int i = 1; i < n; ++i) {
        int a, b;
        cin >> a >> b;
        G[a].push_back(b);
        G[b].push_back(a);
    }

    for (int i = 0; i < k; ++i) {
        int x; cin >> x;
        has[x] = 1;
    }

    dfs(1,1,0);

    cout << ans << endl;

    cerr _ "meow" _ endl;

    return 0;
}