#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define task "slingshot"
#define pll pair<ll, ll>
#define pii pair<pll, ll>
#define fi first
#define se second
#define ull unsigned long long
using namespace std;
const ll mod = 2111992;
const ll N = 5e5+5;
const int base = 300;
ll n, m, t, ans, k, a[N], b[N], c[N], tong, cnt, q, d[N], P[N][21], h[N], lab[N];
mt19937_64 mt(chrono::steady_clock::now().time_since_epoch().count());
struct point
{
ll x, y;
}p[N];
vector<ll> dx, dy;
vector<ll> adj[N], kq, gr[N];
string s[N];
ll pw(ll k, ll n)
{
ll total = 1;
for(; n; n >>= 1)
{
if(n & 1)total = total * k % mod;
k = k * k % mod;
}
return total;
}
ll A(ll u, ll v)
{
if(u > v)return 0;
return b[v] * c[v-u] % mod;
}
ll findp(ll u)
{
return lab[u] < 0 ? u : lab[u] = findp(lab[u]);
}
void hop(ll u, ll v)
{
u = findp(u);
v = findp(v);
if(u == v)return;
if(lab[u] > lab[v])swap(u, v);
lab[u] += lab[v];
lab[v] = u;
}
void add(ll id)
{
for(; id <= n;id += id & -id)++d[id];
}
ll get(ll id)
{
ll total = 0;
for(; id; id -= id & -id)total += d[id];
return total;
}
ll lwr(ll x)
{
return lower_bound(kq.begin(), kq.end(), x) - kq.begin() + 1;
}
void dfs(ll u, ll p)
{
a[u] = ++m;
for(int i = 1; i <= 20; i ++)P[u][i] = P[P[u][i-1]][i-1];
for(ll v : adj[u])
{
if(v == p)continue;
h[v] = h[u] + 1;
P[v][0] = u;
dfs(v, u);
}
}
bool cmp(const ll& x, const ll& y)
{
return a[x] < a[y];
}
ll lca(ll u, ll v)
{
if(h[u] < h[v])swap(u, v);
ll log = log2(h[u]);
for(int i = log; i >= 0; i --)if(h[u] >= h[v] + (1<<i))u = P[u][i];
if(u == v)return u;
for(int i = log; i >= 0; i --)
{
if(P[u][i] && P[u][i] != P[v][i])
{
u = P[u][i];
v = P[v][i];
}
}
return P[u][0];
}
void cal(ll u, ll p)
{
for(ll v : adj[u])
{
if(v == p)continue;
cal(v, u);
c[u] += c[v];
}
if(c[u])hop(u, P[u][0]);
}
void sol()
{
cin >> n >> k;
for(int i = 1; i < n; i ++)
{
ll x, y;
cin >> x >> y;
p[i].x = x;
p[i].y = y;
adj[x].pb(y);
adj[y].pb(x);
}
for(int i = 1; i <= n; i ++)
{
cin >> b[i];
gr[b[i]].pb(i);
}
dfs(1, 0);
for(int i = 1; i <= k; i ++)
{
sort(gr[i].begin(), gr[i].end(), cmp);
for(int j = 1; j < gr[i].size(); j ++)
{
ll x = gr[i][j], y = gr[i][j-1], z = lca(x, y);
++c[x];
++c[y];
c[z] -= 2;
}
}
fill_n(lab, n+2, -1);
cal(1, 0);
for(int i = 1; i < n; i ++)
{
ll u = findp(p[i].x), v = findp(p[i].y);
if(u != v)
{
++d[u];
++d[v];
}
}
for(int i = 1; i <= n; i ++)ans += (d[i] == 1);
cout << (ans + 1) / 2;
}
int main()
{
if(fopen(task".in", "r")){
freopen(task".in", "r", stdin);
freopen(task".out", "w", stdout);
}
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int ntest = 1;
//cin >> ntest;
while(ntest -- > 0)
sol();
}
