#include<bits/stdc++.h>
#define Task "test"
#define ll long long
#define pb emplace_back
#define mp make_pair
#define fi first
#define se second
using namespace std;
const int N = int(2e5) + 5;
typedef pair<int, int> pii;
vector<int> a[N];
int sz[N], n, k, u, v, nstate, full, res = 0;
int cnt[N], s[N], orgcnt[N], f[N];
bool big[N], choose[N];
void DFS(int u, int par) {
sz[u] = 1;
for(int i = 0; i < int(a[u].size()); ++i) {
if(a[u][i] == par) swap(a[u][i], a[u].back());
if(a[u][i] != par) DFS(a[u][i], u), sz[u] += a[u][i];
}
if(u != 1) a[u].pop_back();
}
void Add(int u, int val) {
if(cnt[s[u]] == 0) ++nstate;
if(cnt[s[u]] == orgcnt[s[u]]) --full;
cnt[s[u]] += val;
if(cnt[s[u]] == orgcnt[s[u]]) ++full;
if(cnt[s[u]] == 0) --nstate;
for(int v: a[u])
if(!big[v]) Add(v, val);
}
void DSU(int u, bool keep) {
int Big = 0;
for(int v: a[u])
if(sz[v] > sz[Big]) Big = v;
for(int v: a[u])
if(v != Big) DSU(v, 0);
if(Big) DSU(Big, 1), big[Big] = 1;
Add(u, 1);
if(full == nstate) choose[u] = 1;
if(!keep) Add(u, -1);
}
void _DFS(int u) {
for(int v: a[u]) {
_DFS(v);
f[u] = max(f[u], f[v]);
}
if(choose[u] && !f[u]) ++res;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0), cout.tie(0);
if(fopen(Task".inp", "r")) {
freopen(Task".inp", "r", stdin);
freopen(Task".out", "w", stdout);
}
cin >> n >> k;
for(int i = 1; i < n; ++i) {
cin >> u >> v;
a[u].pb(v), a[v].pb(u);
}
for(int i = 1; i <= n; ++i) cin >> s[i], ++orgcnt[s[i]];
DFS(1, 1); DSU(1, 1);
_DFS(1);
cout << res / 2;
}
