#include <bits/stdc++.h>
#define ar array
//#define int long long
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
const int mod = 1e9 + 7;
const ll inf = 1e18;
const int maxn = 5e5 + 5;
struct union_find {
int n;
vector<int> par, size;
union_find(int _n) : n(_n), par(n+1), size(n+1, 1) {
for(int i=1; i<=n; i++) par[i] = i;
}
int find(int u) {
if(u == par[u]) return u;
return par[u] = find(par[u]);
}
void uni(int a, int b) {
a = find(a); b = find(b);
if(a == b) return ;
if(size[a] < size[b]) swap(a, b);
size[a] += size[b];
par[b] = a;
}
} dsu(maxn);
int n, k, in[maxn], out[maxn], mnT[maxn], mxT[maxn], mn[maxn], mx[maxn], t[maxn], timer = 0;
vector<int> G[maxn];
void dfs(int u, int p) {
in[u] = timer++;
mnT[t[u]] = min(mnT[t[u]], in[u]);
mxT[t[u]] = max(mxT[t[u]], in[u]);
for(int v : G[u])
if(v != p) dfs(v, u);
out[u] = timer - 1;
}
bool anc(int u, int x) {
return in[u] <= x && x <= out[u];
}
void dfs2(int u, int p) {
mn[u] = mnT[t[u]];
mx[u] = mxT[t[u]];
for(int v : G[u]) {
if(v == p) continue;
dfs2(v, u);
mn[u] = min(mn[u], mn[v]);
mx[u] = max(mx[u], mx[v]);
}
if(!anc(u, mn[u]) || !anc(u, mx[u]) && u != 1)
dsu.uni(u, p);
}
signed main() {
ios_base::sync_with_stdio(false);
cout.tie(0); cin.tie(0);
cin >> n >> k;
vector<pii> E;
for(int i=1; i<n; i++) {
int a, b; cin >> a >> b;
E.push_back({ a, b });
G[a].push_back(b);
G[b].push_back(a);
}
for(int i=1; i<=k; i++) mnT[i] = 1e9;
for(int i=1; i<=n; i++) cin >> t[i];
dfs(1, 1);
dfs2(1, 1);
int ans = 0;
set<pii> st;
for(auto [a, b] : E) {
int x = min(dsu.find(a), dsu.find(b));
int y = max(dsu.find(a), dsu.find(b));
st.insert({ x, y });
}
vector<int> deg(n+1);
for(auto [a, b] : st) {
deg[a]++;
deg[b]++;
}
for(int i=1; i<=n; i++)
if(deg[i] == 1) ans++;
cout << (ans + 1) / 2 << '\n';
}
