#define DEBUG 0
#include <bits/stdc++.h>
using namespace std;
#if DEBUG
// basic debugging macros
int __i__,__j__;
#define printLine(l) for(__i__=0;__i__<l;__i__++){cout<<"-";}cout<<endl
#define printLine2(l,c) for(__i__=0;__i__<l;__i__++){cout<<c;}cout<<endl
#define printVar(n) cout<<#n<<": "<<n<<endl
#define printArr(a,l) cout<<#a<<": ";for(__i__=0;__i__<l;__i__++){cout<<a[__i__]<<" ";}cout<<endl
#define print2dArr(a,r,c) cout<<#a<<":\n";for(__i__=0;__i__<r;__i__++){for(__j__=0;__j__<c;__j__++){cout<<a[__i__][__j__]<<" ";}cout<<endl;}
#define print2dArr2(a,r,c,l) cout<<#a<<":\n";for(__i__=0;__i__<r;__i__++){for(__j__=0;__j__<c;__j__++){cout<<setw(l)<<setfill(' ')<<a[__i__][__j__]<<" ";}cout<<endl;}
// advanced debugging class
// debug 1,2,'A',"test";
class _Debug {
public:
template<typename T>
_Debug& operator,(T val) {
cout << val << endl;
return *this;
}
};
#define debug _Debug(),
#else
#define printLine(l)
#define printLine2(l,c)
#define printVar(n)
#define printArr(a,l)
#define print2dArr(a,r,c)
#define print2dArr2(a,r,c,l)
#define debug
#endif
// define
#define MAX_VAL 999999999
#define MAX_VAL_2 999999999999999999LL
#define EPS 1e-6
#define mp make_pair
#define pb push_back
// typedef
typedef unsigned int UI;
typedef long long int LLI;
typedef unsigned long long int ULLI;
typedef unsigned short int US;
typedef pair<int,int> pii;
typedef pair<LLI,LLI> plli;
typedef vector<int> vi;
typedef vector<LLI> vlli;
typedef vector<pii> vpii;
typedef vector<plli> vplli;
// ---------- END OF TEMPLATE ----------
vi adjList[500000];
vi states[500000];
int parent[500000],depth[500000];
int doDFS(int u,int p,int d) {
int i;
parent[u] = p,depth[u] = d;
for (i = 0; i < adjList[u].size(); i++) {
int v = adjList[u][i];
if (v != p) doDFS(v,u,d+1);
}
return 0;
}
int ds[500000],deg[500000];
int find(int n) {
if (ds[n] != n) ds[n] = find(ds[n]);
return ds[n];
}
int main() {
int i;
int N,K;
int A,B,S;
scanf("%d %d",&N,&K);
for (i = 0; i < N-1; i++) {
scanf("%d %d",&A,&B);
A--,B--;
adjList[A].pb(B);
adjList[B].pb(A);
}
for (i = 0; i < N; i++) scanf("%d",&S),states[S-1].pb(i);
int j;
doDFS(0,-1,0);
for (i = 0; i < N; i++) ds[i] = i;
for (i = 0; i < K; i++) {
for (j = 1; j < states[i].size(); j++) {
int u = find(states[i][j-1]),v = find(states[i][j]);
while (u != v) {
if (depth[u] < depth[v]) swap(u,v);
ds[u] = find(parent[u]),u = find(u);
}
}
}
int ans = 0;
for (i = 0; i < N; i++) {
for (j = 0; j < adjList[i].size(); j++) {
int v = adjList[i][j];
if (find(i) != find(v)) deg[find(i)]++;
}
}
for (i = 0; i < N; i++) {
if ((ds[i] == i) && (deg[i] == 1)) ans++;
}
printf("%d\n",(ans+1)/2);
return 0;
}
