#include <bits/stdc++.h>
// #pragma GCC optimize("O3", "unroll-loops")
#define ll long long
#define int long long
#define pb push_back
#define fi first
#define se second
#define lf (id<<1)
#define rg ((id<<1)|1)
#define md ((l+r)>>1)
#define ld long double
using namespace std;
typedef pair<int,int> pii;
typedef pair<pii, int> ipii;
const int MAXN = 5e5+10;
const int MAXA = 9e3+20;
const ll INF = 1e9+10;
const int LOG = 13;
const int SQRT = 450;
const vector<int> NOL = {};
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const vector<int> dx = {1, -1, 0, 0};
const vector<int> dy = {0, 0, 1, -1};
vector <int> key = {29, 31};
vector <int> mod = {998244353, 1000000007};
void chmx(int &a, int b){ a = max(a, b); }
int n, k;
vector <int> adj[MAXN], vec[MAXN];
int a[MAXN], tot[MAXN], u[MAXN], v[MAXN];
struct dsu {
int par[MAXN], siz[MAXN];
void bd(){
for(int i=1; i<=n; i++){
par[i] = i; siz[i] = 1;
}
}
int f(int x){
if(par[x]==x) return x;
return par[x] = f(par[x]);
}
bool con(int x, int y){ return f(x) == f(y); }
void mer(int x, int y){
x = f(x); y = f(y);
if(x==y) return;
if(siz[x] > siz[y]) swap(x, y);
par[x] = y; siz[y] += siz[x];
}
} DSU;
int col;
int dfs(int nw, int par){
int sub = 0;
if(a[nw]==col) sub++;
for(auto nx : adj[nw]){
if(nx==par) continue;
sub += dfs(nx, nw);
}
if(sub!=0 && par!=0){
DSU.mer(nw, par);
// cout << nw << ' ' << par << " par\n";
}
return sub;
}
vector <int> edge[MAXN];
signed main(){
// ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin >> n >> k; DSU.bd();
for(int i=1; i<=n-1; i++){
int x, y; cin >> x >> y; u[i] = x; v[i] = y;
adj[x].pb(y); adj[y].pb(x);
}
for(int i=1; i<=n; i++){
cin >> a[i]; tot[a[i]]++;
vec[a[i]].pb(i);
}
for(int i=1; i<=k; i++){
col = i;
dfs(vec[i][0], 0);
}
for(int i=1; i<=n-1; i++){
int x = DSU.f(u[i]), y = DSU.f(v[i]);
if(x == y) continue;
edge[x].pb(y); edge[y].pb(x);
}
int tot = 0;
for(int i=1; i<=n; i++){
if(edge[i].size() == 1) tot++;
}
cout << (tot+1)/2 << '\n';
}
