#include <bits/stdc++.h>
using namespace std;
#define fo(i,s,t) for(int i = s; i <= t; ++ i)
#define fd(i,s,t) for(int i = s; i >= t; -- i)
#define bf(i,s) for(int i = head[s]; i; i = e[i].next)
#define mp make_pair
#define fi first
#define se second
#define pii pair<int,int>
#define pb push_back
#define VI vector<int>
#define sf scanf
#define pf printf
#define fp freopen
#define SZ(x) ((int)(x).size())
#ifdef MPS
#define D(x...) printf(x)
#else
#define D(x...)
#endif
typedef long long ll;
typedef double db;
typedef unsigned long long ull;
const int inf = 1<<30;
const ll INF = 1ll<<60;
const db Inf = 1e20;
const db eps = 1e-9;
void gmax(int &a,int b){a = (a > b ? a : b);}
void gmin(int &a,int b){a = (a < b ? a : b);}
const int maxn = 500050;
int n, K, fa[maxn], par[maxn], dep[maxn], deg[maxn];
VI adj[maxn], col[maxn];
int getfa(int x) {return fa[x] == x ? x : fa[x] = getfa(fa[x]);}
void merge(int u, int v) {u = getfa(u); v = getfa(v); fa[u] = v;}
void combine(int u, int v)
{
while(u != v)
{
if(dep[u] > dep[v])
{
merge(u, par[u]);
u = getfa(par[u]);
}
else
{
merge(v, par[v]);
v = getfa(par[v]);
}
}
}
void dfs(int u, int f = 0)
{
for(auto p : adj[u]) if(p != f)
{
par[p] = u;
dep[p] = dep[u] + 1;
dfs(p, u);
}
}
int main()
{
#ifdef MPS
fp("1.in","r",stdin);
fp("1.out","w",stdout);
#endif
sf("%d%d",&n,&K);
fo(i,2,n)
{
int u, v; sf("%d%d",&u,&v);
adj[u].pb(v); adj[v].pb(u);
}
fo(i,1,n) fa[i] = i;
fo(i,1,n) {int x; sf("%d",&x); col[x].pb(i);}
dfs(1);
fo(i,1,K) fo(j,1,SZ(col[i])-1) combine(col[i][j], col[i][0]);
fo(i,1,n) for(auto p : adj[i])
if(getfa(i) != getfa(p) && dep[i] + 1 == dep[p])
{
++ deg[getfa(i)]; ++ deg[getfa(p)];
}
int leaves = 0;
fo(i,1,n) if(getfa(i) == i && deg[i] == 1) ++ leaves;
pf("%d\n",(int)ceil(leaves/2.0));
return 0;
}
