// oooo
/*
har chi delet mikhad bebar ~
gitar o ba khodet nabar! ~
;Amoo_Hasan;
*/
#include<bits/stdc++.h>
//#pragma GCC optimize("O3,no-stack-protector,unroll-loops")
//#pragma GCC target("avx2,fma")
using namespace std;
typedef long long ll;
typedef long double ld;
#define Sz(x) int((x).size())
#define All(x) (x).begin(), (x).end()
#define wtf(x) cout<<#x <<" : " <<x <<endl
#define mak make_pair
//constexpr int PRI = 1000696969;
constexpr ll INF = 1e18, N = 1e6 + 10, MOD = 1e9 + 7, LOG = 20;
int s[N];
int par[N][LOG], h[N], st[N], fn[N], tim;
int sz[N], pv[N];
int ans;
vector<int> vc[N], adj[N], nei[N];
void dfs(int x, int p = -1) {
par[x][0] = p;
for(int i = 1; i < LOG; i++) par[x][i] = par[par[x][i - 1]][i - 1];
h[x] = h[p] + 1;
st[x] = tim++;
for(auto j : adj[x]) {
if(j == p) continue;
dfs(j, x);
}
fn[x] = tim;
}
int get_par(int x, int y) {
for(int i = 0; i < LOG; i++)
if((y >> i) & 1)
x = par[x][i];
return x;
}
int lca(int x, int y) {
if(h[x] > h[y]) swap(x, y);
y = get_par(y, h[y] - h[x]);
if(x == y) return x;
for(int i = LOG - 1; i >= 0; i--)
if(par[x][i] != par[y][i])
x = par[x][i], y = par[y][i];
return par[x][0];
}
int find(int x) {
if(pv[x] == x) return x;
return pv[x] = find(pv[x]);
}
void merge(int x, int y) {
int X = find(x), Y = find(y);
if(X == Y) return;
if(sz[X] < sz[Y]) swap(X, Y);
pv[Y] = X, sz[X] += sz[Y];
}
bool cmp(int i, int j) {
return st[i] < st[j];
}
void solve(int x) {
vector<int> ver;
for(auto i : vc[x]) ver.push_back(i);
sort(All(ver), cmp);
int sz = Sz(ver);
for(int i = 1; i < sz; i++) {
ver.push_back(lca(ver[i - 1], ver[i]));
}
sort(All(ver), cmp);
ver.erase(unique(All(ver)), ver.end());
stack<int> mt;
mt.push(ver[0]);
merge(ver[0], x);
for(int i = 1; i < Sz(ver); i++) {
int v = ver[i];
while(fn[mt.top()] < fn[v]) mt.pop();
int p = mt.top();
merge(x, v);
v = par[v][0];
while(v != p) {
merge(x, v);
v = par[v][0];
}
mt.push(v);
}
}
int main() {
ios :: sync_with_stdio(0), cin.tie(0); cout.tie(0);
for(int i = 0; i < N; i++) sz[i] = 1, pv[i] = i;
int n, k; cin >>n >>k;
for(int i = 0; i < n - 1; i++) {
int u, v; cin >>u >>v;
--u, --v;
adj[u].push_back(v), adj[v].push_back(u);
}
for(int i = 0; i < n; i++) {
cin >>s[i];
--s[i], s[i] += n;
vc[s[i]].push_back(i);
}
dfs(0);
for(int i = n; i < n + k; i++) {
solve(i);
}
for(int i = 0; i < n; i++) {
for(auto j : adj[i]) {
if(pv[j] == pv[i]) continue;
nei[pv[j]].push_back(pv[i]);
nei[pv[i]].push_back(pv[j]);
}
}
for(int i = 0; i < N; i++) {
nei[i].erase(unique(All(nei[i])), nei[i].end());
if(Sz(nei[i]) == 1) ans++;
}
cout<<(ans + 1) / 2;
return 0;
}
