#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
template <class T>
inline bool Min(T &a, T b) {
  return a > b ? (a = b, true) : false;
}
template <class T>
inline bool Max(T &a, T b) {
  return a < b ? (a = b, true) : false;
}
inline int ni() {
  int a;
  scanf("%d", &a);
  return a;
}
inline ll nl() {
  ll a;
  scanf("%lld", &a);
  return a;
}
inline double nd() {
  double a;
  scanf("%lf", &a);
  return a;
}
inline void pi(int a) { printf("%d ", a); }
inline void pl(ll a) { printf("%lld ", a); }
inline void pd(double a) { printf("%.12lf ", a); }
const int N = 2e5 + 100;
vector<int> gp[N];
bool is_university[N];
int n, k;
int cnt[N];
ll ans = 0;
void dfs(int v, int p) {
  cnt[v] = is_university[v];
  for (int next : gp[v])
    if (next != p)
      dfs(next, v), cnt[v] += cnt[next],
          ans += min(cnt[next], k + k - cnt[next]);
}
void solve() {
  n = ni();
  k = ni();
  for (int i = 0; i < (int)(k + k); ++i) is_university[ni()] = true;
  for (int i = 0; i < (int)(n - 1); ++i) {
    int a = ni();
    int b = ni();
    gp[a].push_back(b);
    gp[b].push_back(a);
  }
  dfs(1, 1);
  pl(ans);
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  solve();
  return 0;
}
