#include <iostream>
// #include <cassert>
#include <set>
using namespace std;
int n, m;
int a[200005];
int head[200005], nxt[400005], to[400005], ecnt;
void add(int u, int v) { to[++ecnt] = v, nxt[ecnt] = head[u], head[u] = ecnt; }
int top[200005], dep[200005], son[200005], sz[200005], f[200005];
int dfn[200005], _dfn[200005], ncnt;
void dfs1(int x, int fa, int d) {
    dep[x] = d;
    f[x] = fa;
    sz[x] = 1;
    for (int i = head[x]; i; i = nxt[i]) {
        int v = to[i];
        if (v != fa) {
            dfs1(v, x, d + 1);
            sz[x] += sz[v];
            if (sz[v] > sz[son[x]]) 
                son[x] = v;
        }
    }
}
void dfs2(int x, int t) {
    top[x] = t;
    _dfn[dfn[x] = ++ncnt] = x;
    if (!son[x]) 
        return;
    dfs2(son[x], t);
    for (int i = head[x]; i; i = nxt[i]) {
        int v = to[i];
        if (v != f[x] && v != son[x]) 
            dfs2(v, v);
    }
}
int LCA(int x, int y) {
    while (top[x] ^ top[y]) (dep[top[x]] < dep[top[y]]) ? (y = f[top[y]]) : (x = f[top[x]]);
    return (dep[x] < dep[y] ? x : y);
}
int dist(int x, int y) { return dep[x] + dep[y] - 2 * dep[LCA(x, y)]; }
set<int> st;
int cur = 0;
void Add(int x) {
    if (x == 1) 
        return;
    int a, b;
    int d = dfn[x];
    set<int>::iterator it = st.upper_bound(d);
    b = (it != st.end() ? _dfn[*it] : _dfn[*st.begin()]);
    // assert(it != st.begin());
    --it;
    a = _dfn[*it];
    cur -= dist(a, b);
    cur += dist(a, x);
    cur += dist(b, x);
    st.insert(dfn[x]);
}
void Erase(int x) {
    if (x == 1) 
        return;
    int a, b;
    int d = dfn[x];
    st.erase(st.find(d));
    set<int>::iterator it = st.upper_bound(d);
    b = (it != st.end() ? _dfn[*it] : _dfn[*st.begin()]);
    // assert(it != st.begin());
    --it;
    a = _dfn[*it];
    cur += dist(a, b);
    cur -= dist(a, x);
    cur -= dist(b, x);
}
int dp[505][30005];
int _l = 1, _r;
void Move(int tl, int tr) {
    while (_r < tr) Add(a[++_r]);
    while (_r > tr) Erase(a[_r--]);
    while (_l < tl) Erase(a[_l++]);
    while (_l > tl) Add(a[--_l]);
}
void Solve(int l, int r, int L, int R, int k) {
    if (l > r) 
        return;
    int mid = (l + r) >> 1;
    int p = L;
    for (int i = L; i <= mid; i++) {
        Move(i, mid);
        if (dp[k - 1][i - 1] + cur > dp[k][mid]) {
            dp[k][mid] = dp[k - 1][i - 1] + cur;
            p = i;
        }
    }
    // cout << k << " " << mid << " " << p << " " << dp[k][mid] << "\n";
    Solve(l, mid - 1, L, p, k);
    Solve(mid + 1, r, p, R, k);
}
int main() {
    cin >> n >> m;
    for (int i = 1; i <= n; i++) cin >> a[i];
    for (int i = 1; i < n; i++) {
        int u, v;
        cin >> u >> v;
        add(u, v);
        add(v, u);
    }
    dfs1(1, 0, 1);
    dfs2(1, 1);
    st.insert(1);
    for (int i = 1; i <= n; i++) {
        Add(a[i]);
        dp[1][i] = cur;
        // cout << i << " " << dp[1][i] << "\n";
    }
    for (int i = 1; i <= n; i++) Erase(a[i]);
    for (int i = 2; i <= m; i++) Solve(i, n, i, n, i);
    cout << dp[m][n] << "\n";
    return 0;
}