#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
const int maxn=5e4+5;
int n,k,fk,a[maxn],p[13];
int siz[maxn],son[maxn],vis[maxn],root,MAX,cnt,num[1030],d[maxn],cn=0,head[maxn];
LL ans=0;
struct Edge
{
    int to,next;
}edge[2*maxn];
inline void add_edge(int from,int to)
{
    edge[cn].to=to;
    edge[cn].next=head[from];
    head[from]=cn++;
}
inline void init()
{
    cn=0;
    fk=(1<<k)-1;
    ans=0;
    for(int i=0;i<=n;i++)vis[i]=0;
        memset(head,-1,sizeof(head));
}
void get_siz(int cur,int fa)
{
    siz[cur]=1;
    son[cur]=0;
    for(int i=head[cur];i!=-1;i=edge[i].next)
    {
        int x=edge[i].to;
        if(x==fa||vis[x])continue;
        get_siz(x,cur);
        siz[cur]+=siz[x];
        if(siz[x]>son[cur])son[cur]=siz[x];
    }
}
void find_root(int cur,int fa,int rt)
{
    if(siz[rt]-siz[cur]>son[cur])son[cur]=siz[rt]-siz[cur];
    if(son[cur]<MAX)MAX=son[cur],root=cur;
    for(int i=head[cur];i!=-1;i=edge[i].next)
    {
        int x=edge[i].to;
        if(x==fa||vis[x])continue;
        find_root(x,cur,rt);
    }
}
void get_state(int cur,int fa,int sta)
{
    d[cnt++]=sta;
    num[sta]++;
    for(int i=head[cur];i!=-1;i=edge[i].next)
    {
        int x=edge[i].to;
        if(vis[x]||x==fa)continue;
        get_state(x,cur,a[x]|sta);
    }
}
LL cal(int cur,int sta)
{
    cnt=0;
    memset(num,0,sizeof(num));
    get_state(cur,0,sta);
    for(int i=0;i<k;i++)
    {
        for(int j=fk;j>=0;j--)
        {
            if(!(p[i]&j))num[j]+=num[j|p[i]];
        }
    }
    LL ret=0;
    for(int i=0;i<cnt;i++)ret=ret+num[fk^d[i]];
    return ret;
}
void dfs(int cur)
{
    MAX=n;
    get_siz(cur,0);
    find_root(cur,0,cur);
    int Root=root;
    ans=ans+cal(root,a[Root]);
    vis[root]=1;
    for(int j=head[Root];j!=-1;j=edge[j].next)
    {
        int x=edge[j].to;
        if(vis[x])continue;
        ans=ans-cal(x,(a[x]|a[Root]));
        dfs(x);
    }
}
int main()
{
    p[0]=1;for(int i=1;i<=11;i++)p[i]=p[i-1]*2;
    while(scanf("%d%d",&n,&k)!=EOF)
    {
        init();
        for(int i=1;i<=n;i++)
        {
            scanf("%d",&a[i]);
            a[i]=p[a[i]-1];
        }
        int u,v;
        for(int i=1;i<n;i++)
        {
            scanf("%d%d",&u,&v);
            add_edge(u,v);
            add_edge(v,u);
        }
        dfs(1);
        printf("%lld\n",ans);
    }
    return 0;
}