#include <bits/stdc++.h>
using namespace std;
#define int long long
#define sp << ' ' <<
#define nl << '\n'
const int MAXN = 5e5;
array<int, 20> p[MAXN];
vector<int> g[MAXN];
int t0[MAXN], d[MAXN], pre[MAXN], dfsTimer = 0;
void dfs0(int u, int par, int dep){
t0[u] = dfsTimer++;
p[u][0] = par, d[u] = dep;
for(int i=0; i<19; ++i) p[u][i+1] = p[p[u][i]][i];
for(int v : g[u]) if(v != par) dfs0(v, u, dep + 1);
}
int lca(int u, int v){
if(d[u] < d[v]) swap(u, v);
for(int i=0; i<20; ++i) if((d[u]-d[v]) & (1<<i)) u = p[u][i];
if(u == v) return u;
for(int i=19; i>=0; --i) if(p[u][i] != p[v][i]) u = p[u][i], v = p[v][i];
return p[u][0];
}
vector<int> e(MAXN, -1);
int find(int u){
return e[u] < 0 ? u : e[u] = find(e[u]);
}
void unite(int u, int v){
u = find(u), v = find(v);
if(u==v) return;
if(e[u] > e[v]) swap(u, v);
e[u] += e[v], e[v] = u;
}
void dfs1(int u){
for(int v : g[u]){
if(v == p[u][0]) continue;
dfs1(v);
pre[u] += pre[v];
if(pre[v]) unite(u, v);
}
}
signed main(){
cin.tie(0)->sync_with_stdio(0);
int n, k, u, v; cin >> n >> k;
for(int i=1; i<n; ++i){
cin >> u >> v; --u, --v;
g[u].push_back(v);
g[v].push_back(u);
}
vector<int> c[k];
for(u=0; u<n; ++u) cin >> v, c[v-1].push_back(u);
dfs0(0, 0, 0);
for(auto &i : c){
sort(i.begin(), i.end(), [&](int x, int y){
return t0[x] < t0[y];
});
i.push_back(i.front());
for(int j=0; j+1<(int)i.size(); ++j){
++pre[i[j]];
++pre[i[j+1]];
pre[lca(i[j], i[j+1])] -= 2;
}
}
dfs1(0);
vector<int> h(n);
for(int u=0; u<n; ++u)
for(int v : g[u])
if(find(u) != find(v)) ++h[find(u)], ++h[find(v)];
int ans = 0;
for(int u=0; u<n; ++u){
ans += find(u) == u && h[find(u)] == 2;
}
cout << (ans + 1) / 2;
}
