// start time : 21 : 55

#include <bits/stdc++.h>

#define rep(i,l,r) for (int i = l; i <= r; i++)
#define per(i,r,l) for (int i = r; i >= l; i--)
#define fi first
#define se second
#define pb push_back
#define mp std::make_pair
#define gin std::cin
#define prt std::cout
#define edl std::endl

namespace Main {
  const int N = 2e5 + 5;
  int n,k,p[N];
  int head[N],edge[N << 1],fail[N << 1],tot;
  int dfn[N],idx[N],fa[20][N],dep[N],cnt;
  std::set<int> S;
  int curl,curr;
  long long curans,f[N],g[N];
  void add(int x,int y) {
    edge[++ tot] = y,fail[tot] = head[x],head[x] = tot;
  }
  void dfs(int x) {
    dfn[x] = ++ cnt; idx[cnt] = x;
    rep(i,1,19) fa[i][x] = fa[i - 1][fa[i - 1][x]];
    for (int i = head[x]; i; i = fail[i]) {
      int v = edge[i];
      if (v == fa[0][x]) continue;
      fa[0][v] = x; dep[v] = dep[x] + 1; 
      dfs(v);
    }
  }
  int lca(int x,int y) {
    if (dep[x] < dep[y]) std::swap(x,y);
    int delta = dep[x] - dep[y];
    rep(i,0,19) if (delta >> i & 1) x = fa[i][x];
    if (x == y) return x;
    per(i,19,0) if (fa[i][x] != fa[i][y]) x = fa[i][x],y = fa[i][y];
    return fa[0][x];
  }
  int dist(int x,int y) {
    return dep[x] + dep[y] - 2 * dep[lca(x,y)];
  }
  void insert(int x) {
    if (x == 1) return;
    auto it = S.upper_bound(x);
    if (it == S.end()) {
      -- it; int pre = idx[*it];
      curans -= dist(1,pre); curans += dist(1,x); curans += dist(pre,x);
    } else {
      int next = idx[*it]; -- it; int pre = idx[*it];
      curans -= dist(pre,next); curans += dist(pre,x); curans += dist(x,next);
    }
    S.insert(dfn[x]);
  }
  void delet(int x) {
    if (x == 1) return;
    S.erase(dfn[x]);
    auto it = S.upper_bound(x);
    if (it == S.end()) {
      -- it; int pre = idx[*it];
      curans -= dist(pre,x); curans -= dist(1,x); curans += dist(1,pre);
    } else {
      int next = idx[*it]; -- it; int pre = idx[*it];
      curans -= dist(pre,x); curans -= dist(x,next); curans += dist(pre,next);
    }
  }
  void solve(int l,int r,int x,int y) {
    if (l > r) return;
    int mid = (l + r) >> 1,pos = x;
    rep(j,x,std::min(mid,y)) {
      while (curr < mid) {
        ++ curr; insert(p[curr]);
      }
      while (curl > j) {
        -- curl; insert(p[curl]);
      }
      while (curr > mid) {
        delet(p[curr]); -- curr;
      }
      while (curl < j) {
        delet(p[curl]); ++ curl;
      }
      if (g[j - 1] + curans >= f[mid]) {
        pos = j; f[mid] = g[j - 1] + curans;
      }
    }
    solve(l,mid - 1,x,pos); solve(mid + 1,r,pos,y);
  }
  void main() {
    scanf("%d%d",&n,&k); rep(i,1,n) scanf("%d",&p[i]);
    rep(i,1,n - 1) {
      int x,y; scanf("%d%d",&x,&y); add(x,y); add(y,x);
    }
    dep[0] = -1; dfs(1);
    rep(i,1,n) f[i] = -1000000000000000000;
    rep(i,1,k) {
      rep(j,0,n) g[j] = f[j];
      rep(j,0,n) f[j] = -1000000000000000000;
      curl = 1; curr = 0; curans = 0; S.clear(); S.insert(1); solve(1,n,1,n);
    }
    prt << f[n];
  }
} signed main() { Main::main(); return 0; }