#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int,int>;
int dfs(int cur, int pre, vector<vector<int>> &v, vector<int> &cnt,set<int> &st){
        int tmp = 0;
        if(st.find(cur) != st.end())
                tmp = 1;

        for(int i : v[cur]){
                if(i == pre){
                        continue;
                }
                tmp += dfs(i, cur, v, cnt, st);
        }
        cnt[cur] = tmp;
        return tmp > 0;
}
void ff(int cur, int pre, vector<vector<int>> &v, vector<int> &cnt){
        if(cnt[pre] > cnt[cur])
                cnt[cur] += 1;

        for(int it : v[cur]){
                if(it == pre)
                        continue;
                ff(it, cur, v, cnt);
        }
}
void solve(){
        int n,k;
        cin >> n >> k;
        vector<vector<int>> v(n+1);
        for(int i = 0;i < n - 1;i ++){
                int a,b,k;
                cin >> a >> b >> k;
                v[a].emplace_back(b);
                v[b].emplace_back(a);
        }
        set<int> st;
        for(int i = 0;i < k;i ++){
                int x;
                cin >> x;
                st.emplace(x);
        }
        vector<int> cnt(n+1);
        dfs(1, 0, v, cnt, st);
        ff(1, 0, v, cnt);
        int ans = 0;
        for(int i = 0;i < n;i ++){
                if(cnt[i+1] >= 2 || st.find(i+1) != st.end()){
                        ans ++ ;
                }
        }
        cout << ans << "\n";
}
int main(){
        cin.tie(0)->sync_with_stdio(0);
        int t = 1;
        while(t--){
                solve();
        }
}