#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define ull unsigned long long
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<long long, long long>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace __gnu_pbds;
using namespace std;
typedef tree<int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;
//mt19937 mt;void random_start(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());}
//ll los(ll a, ll b) {return a + (mt() % (b-a+1));}
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;
vi graph[500001];
int color[500001];
int precolor[500001];
int pre[500001];
int cur_pre;
bool block[500001];
bool odw[500001];
int P[500001];
vi ls;
int cnt = 0;
void dfs_pre(int v, int pop)
{
P[v] = pop;
ls.pb(v);
pre[v] = cur_pre++;
forall(it,graph[v])
{
if(it != pop)
{
dfs_pre(it,v);
}
}
}
int dfs_block(int v, int pop)
{
int min_ = precolor[color[v]];
forall(it,graph[v])
{
if(it != pop)
{
min_ = min(min_,dfs_block(it,v));
}
}
if(min_ == pre[v] && pop != v) block[v] = 1;
return min_;
}
void dfs_ans(int v, int pop)
{
if(block[v])
{
cnt++;
if(v != pop) return;
}
odw[v] = 1;
forall(it,graph[v])
{
if(it != P[v]) dfs_ans(it,v);
}
}
int main()
{
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
//random_start();
int n,k;
cin >> n >> k;
rep2(i,1,k) precolor[i] = 1e9;
rep(i,n-1)
{
int a,b;
cin >> a >> b;
graph[a].pb(b);
graph[b].pb(a);
}
dfs_pre(1,1);
rep2(i,1,n) cin >> color[i];
rep2(i,1,n) precolor[color[i]] = min(precolor[color[i]],pre[i]);
dfs_block(1,1);
int ans = 0;
forall(it,ls)
{
if(odw[it]) continue;
cnt = 0;
dfs_ans(it,it);
if(cnt <= 1) ans++;
}
cout << ans-1 << "\n";
}
