#include<bits/stdc++.h>
#define f first
#define s second
#define int long long
#define pii pair<int,int>
using namespace std;
const int N = 2e5 + 5, mod = 1e9 + 7; // !
int t, p[N], P[N][20], X[N], in[N], out[N];
int ans = 0, timer = 0;
vector<int> V[N], x[N];
bool cmp(int u, int v) {
return (in[u] < in[v]);
}
int find(int x) {
return (p[x] == x ? x : p[x] = find(p[x]));
}
void dfs0(int u) {
in[u] = ++timer;
for(int i = 1; i <= 18; i++) P[u][i] = P[P[u][i - 1]][i - 1];
for(int i = 0; i < V[u].size(); i++) {
if(V[u][i] == P[u][0]) continue;
P[V[u][i]][0] = u;
dfs0(V[u][i]);
}
out[u] = timer;
}
bool check(int u, int v) {
return (in[u] <= in[v] && out[v] <= out[u]);
}
int lca(int u, int v) {
if(check(u, v)) return u;
if(check(v, u)) return v;
for(int i = 18; i >= 0; i--) {
if(P[u][i] && !check(P[u][i], v)) u = P[u][i];
}
return P[u][0];
}
void up(int u, int v, int lca) {
int cur = u;
while(true) {
cur = find(cur);
if(cur == 1 || find(cur) == find(lca)) break;
p[cur] = find(P[cur][0]);
cur = p[cur];
}
}
void dfs(int u) {
for(int i = 0; i < V[u].size(); i++) {
dfs(V[u][i]);
X[u] += X[V[u][i]];
}
ans += ((int)V[u].size() == 0);
}
main(){
int n, m;
cin >> n >> m;
for(int i =1; i <= n; i++) p[i] = i;
for(int i = 2; i <= n; i++) {
int u, v;
cin >> u >> v;
V[u].push_back(v);
V[v].push_back(u);
}
dfs0(1);
for(int i = 1; i <= n; i++) {
int a; cin >> a;
x[a].push_back(i);
}
for(int i = 1; i <= m; i++) {
sort(x[i].begin(), x[i].end(), cmp);
for(int j = 1; j < x[i].size(); j++) {
int u = x[i][j - 1], v = x[i][j];
int l = lca(u, v);
up(u, v, l);
up(v, u, l);
}
}
for(int i = 1; i <= n; i++) V[i].clear();
for(int i = 2; i <= n; i++) if(find(i) != find(P[i][0])) V[find(P[i][0])].push_back(find(i));
dfs(1);
cout << (ans + 1) /2;
}
