#pragma comment(linker, "/STACK:1024000000,1024000000")

#include <cstdio>

#include <string>

#include <cstdlib>

#include <cmath>

#include <iostream>

#include <cstring>

#include <set>

#include <queue>

#include <algorithm>

#include <vector>

#include <map>

#include <cctype>

#include <cmath>

#include <stack>

#include <sstream>

#include <list>

#include <assert.h>

#define debug() puts("++++");

#define gcd(a, b) __gcd(a, b)

#define lson l,m,rt<<1

#define rson m+1,r,rt<<1|1

#define fi first

#define se second

#define pb push_back

#define sqr(x) ((x)*(x))

#define ms(a,b) memset(a, b, sizeof a)

#define sz size()

#define pu push_up

#define pd push_down

#define FOR(x,n)  for(int i = (x); i < (n); ++i)

#define freopenr freopen("in.txt", "r", stdin)

#define freopenw freopen("out.txt", "w", stdout)

using namespace std;

typedef long long LL;

typedef unsigned long long ULL;

typedef pair<int, int> P;

const int INF = 0x3f3f3f3f;

const double inf = 1e20;

const double PI = acos(-1.0);

const double eps = 1e-8;

const int maxn = 50000 + 10;

const LL mod = 1e9 + 7;

const int dr[] = {-1, 0, 1, 0};

const int dc[] = {0, 1, 0, -1};

const char *de[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"};

int n, m;

const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

inline bool is_in(int r, int c) {

    return r > 0 && r <= n && c > 0 && c <= m;

}

int all;

struct Edge{

  int to, next;

};

Edge edge[maxn<<1];

int head[maxn], cnt;

int val[maxn];

void addEdge(int u, int v){

  edge[cnt].to = v;

  edge[cnt].next = head[u];

  head[u] = cnt++;

}

int root, num, f[maxn];

LL dp[1<<10];

int sum[maxn];

bool vis[maxn];

LL ans;

void dfs_for_root(int u, int fa){

  sum[u] = 1;  f[u] = 0;

  for(int i = head[u]; ~i; i = edge[i].next){

    int v = edge[i].to;

    if(v == fa || vis[v])  continue;

    dfs_for_root(v, u);

    sum[u] += sum[v];

    f[u] = max(f[u], sum[v]);

  }

  f[u] = max(f[u], num - sum[u]);

  if(f[root] > f[u])  root = u;

}

void dfs_for_color(int u, int fa, int s){

  for(int i = head[u]; ~i; i = edge[i].next){

    int v = edge[i].to;

    if(v == fa || vis[v])  continue;

    ++dp[s|1<<val[v]];

    dfs_for_color(v, u, s|1<<val[v]);

  }

}

LL solve(int u, int s){

  ms(dp, 0);

  ++dp[s];

  dfs_for_color(u, -1, s);

  LL ans = 0;

  for(int i = 0; i <= all; ++i){

    if(!dp[i])  continue;

    int tmp = 0;

    tmp += dp[all];

    for(int j = i; j; j = (j-1)&i)

      tmp += dp[all^j];

    ans += (LL)tmp * dp[i];

  }

  return ans;

}

void dfs_for_ans(int u){

  ans += solve(u, 1<<val[u]);

  vis[u] = true;

  for(int i = head[u]; ~i; i = edge[i].next){

    int v = edge[i].to;

    if(vis[v])  continue;

    ans -= solve(v, 1<<val[u]|1<<val[v]);

    root = 0;

    f[0] = num = sum[v];

    dfs_for_root(v, u);

    dfs_for_ans(root);

  }

}

int main(){

  while(scanf("%d %d", &n, &m) == 2){

    for(int i = 1; i <= n; ++i){

      scanf("%d", val+i);

      --val[i];

    }

    all = (1<<m) - 1;

    ms(head, -1);  cnt = 0;

    for(int i = 1; i < n; ++i){

      int u, v;

      scanf("%d %d", &u, &v);

      addEdge(u, v);

      addEdge(v, u);

    }

    ms(vis, 0);

    root = 0;  ans = 0LL;

    f[0] = num = n;

    dfs_for_root(1, -1);

    dfs_for_ans(root);

    printf("%I64d\n", ans);

  }

  return 0;

}