#include <bits/stdc++.h>
using namespace std;
long long int ans = 0;
vector<int> vx[200005];
bool vu[200005];
int n, k;
int dfs(int v, int p) {
  int aa = 0, aa2 = 0;
  for (int i = 0; i < vx[v].size(); i++) {
    if (vx[v][i] == p) continue;
    int pr = dfs(vx[v][i], v);
    aa += pr;
    aa2 += min(pr, 2 * k - pr);
  }
  ans += aa2;
  if (vu[v]) aa++;
  return aa;
}
int main() {
  for (int i = 0; i < 200005; i++) vu[i] = 0;
  cin >> n >> k;
  int u, v;
  for (int i = 0; i < k; i++) {
    cin >> u >> v;
    vu[u] = vu[v] = 1;
  }
  for (int i = 1; i < n; i++) {
    cin >> u >> v;
    vx[u].push_back(v);
    vx[v].push_back(u);
  }
  dfs(1, -1);
  cout << ans;
  return 0;
}
