#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][19],depth[500000];
int doDFS(int u,int p,int d) {
int i;
parent[u][0] = 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 toAdd[500000][19],yes[500000],yes2[500000],r[500000],ans = 0;
int doDFS2(int u,int p) {
int i;
int c = yes[u],n = -1,nc = 0;
yes2[u] = c;
for (i = 0; i < adjList[u].size(); i++) {
int v = adjList[u][i];
if (v != p) {
doDFS2(v,u);
yes[u] += yes[v];
if (yes[v] > 0) n = v,nc++;
}
}
if ((c == 1) && (yes[u] == c)) ans++,r[u] = 1;
if ((nc == 1) && (r[n] || yes2[n])) r[u] = 1;
return 0;
}
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,k;
doDFS(0,-1,0);
for (i = 1; (1 << i) < N; i++) {
for (j = 0; j < N; j++) {
if (parent[j][i-1] != -1) parent[j][i] = parent[parent[j][i-1]][i-1];
else parent[j][i] = -1;
}
}
int logn = i;
for (i = 0; i < K; i++) {
for (j = 1; j < states[i].size(); j++) {
int u = states[i][j-1],v = states[i][j];
if (depth[u] < depth[v]) swap(u,v);
for (k = logn-1; k >= 0; k--) {
if ((parent[u][k] != -1) && (depth[parent[u][k]] >= depth[v]))
toAdd[u][k]++,u = parent[u][k];
}
if (u != v) {
for (k = logn-1; k >= 0; k--) {
if (parent[u][k] != parent[v][k]) {
toAdd[u][k]++,u = parent[u][k];
toAdd[v][k]++,v = parent[v][k];
}
}
toAdd[u][0]++,toAdd[v][0]++;
}
}
}
for (i = logn-1; i >= 1; i--) {
for (j = 0; j < N; j++) {
if (parent[j][i] != -1) {
toAdd[j][i-1] += toAdd[j][i];
toAdd[parent[j][i-1]][i-1] += toAdd[j][i];
}
}
}
for (i = 0; i < N; i++) yes[i] = (i > 0) && (toAdd[i][0] == 0);
doDFS2(0,-1);
if (r[0]) ans++;
printf("%d\n",(ans+1)/2);
return 0;
}
