#include <bits/stdc++.h>
#define task "M"
#define all(v) (v).begin(), (v).end()
#define rep(i, l, r) for (int i = (l); i <= (r); ++i)
#define Rep(i, r, l) for (int i = (r); i >= (l); --i)
#define DB(X) { cerr << #X << " = " << (X) << '\n'; }
#define DB1(A, _) { cerr << #A << "[" << _ << "] = " << (A[_]) << '\n'; }
#define DB2(A, _, __) { cerr << #A << "[" << _ << "][" << __ << "] = " << (A[_][__]) << '\n'; }
#define DB3(A, _, __, ___) { cerr << #A << "[" << _ << "][" << __ << "][" << ___ << "] = " << (A[_][__][___]) << '\n'; }
#define PR(A, l, r) { cerr << '\n'; rep(_, l, r) DB1(A, _); cerr << '\n';}
#define SZ(x) ((int)(x).size())
#define pb push_back
#define eb emplace_back
#define pf push_front
#define F first
#define S second
#define by(x) [](const auto& a, const auto& b) { return a.x < b.x; } // sort(arr, arr + N, by(a));
#define next ___next
#define prev ___prev
#define y1 ___y1
#define left ___left
#define right ___right
#define y0 ___y0
#define div ___div
#define j0 ___j0
#define jn ___jn
using ll = long long;
using ld = long double;
using ull = unsigned long long;
using namespace std;
typedef pair<int, int> ii;
typedef pair<ii, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<ll> vl;
const int N = 5e5 + 2;
int n, numCol, deg[N], rt[N], dep[N], par[N];
vi col[N], g[N];
void dfs(int u)
{
dep[u] = dep[par[u]] + 1;
for (int v : g[u]) if (v != par[u])
{
par[v] = u;
dfs(v);
}
}
int frt(int i) {return rt[i] == i ? i : rt[i] = frt(rt[i]);}
bool in[N];
int main()
{
#ifdef HynDuf
freopen(task".in", "r", stdin);
//freopen(task".out", "w", stdout);
#else
ios_base::sync_with_stdio(false); cin.tie(nullptr);
#endif
cin >> n >> numCol;
rep(I, 2, n)
{
int u, v;
cin >> u >> v;
g[u].eb(v);
g[v].eb(u);
}
dfs(1);
rep(i, 1, n)
{
int c;
cin >> c;
col[c].eb(i);
rt[i] = i;
}
rep(c, 1, numCol)
{
rep(i, 1, SZ(col[c]) - 1)
{
int u = frt(col[c][i - 1]), v = frt(col[c][i]);
while (u != v)
{
if (dep[u] < dep[v]) swap(u, v);
rt[u] = frt(par[u]);
u = rt[u];
}
}
}
vi change;
rep(i, 1, n)
{
for (int v : g[i]) if (frt(v) != frt(i) && !in[frt(v)]) change.eb(frt(v)), in[frt(v)] = 1, deg[frt(v)]++;
for (int v : change) in[v] = 0;
change.clear();
}
int cnt = 0;
rep(i, 1, n) cnt += (deg[i] == 1);
cout << (cnt + 1) / 2;
return 0;
}
