#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define pb push_back
#define gcd(a,b) (__gcd(a,b))
#define lcm(a,b) (a/gcd(a,b)*b)
#define sz(x) (int)(x.size())
#define fast_cin() ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define db(x) cerr << "[" << "Line " << __LINE__ << " : " << (#x) << " = " << x << "] "
typedef pair<int,int> pii;
const int MOD = 1e9 + 7;
const int MAXN1 = 1e5+5;
const int MAXN2 = 1e6+5;
const long long inf = 1e17;
mt19937_64 rng(time(0));
template<class T>
void maximize(T &res, T val) {
res = max(res, val);
}
template <class T>
void minimize(T &res, T val) {
res = min(res, val);
}
const int LOG = 17;
int n,m;
long long w[MAXN1];
long long nei[MAXN1];
int par[MAXN1][LOG + 3];
long long totnei[MAXN1];
long long dist[MAXN1];
int h[MAXN1];
vector<int> adj[MAXN1];
void dfs(int u) {
dist[u] += w[u];
totnei[u] += nei[u];
for(int v : adj[u]) {
if(v == par[u][0]) continue;
h[v] = h[u] + 1;
par[v][0] = u;
totnei[v] = totnei[u];
dist[v] = dist[u];
for(int i = 1; i <= LOG; ++i) par[v][i] = par[par[v][i - 1]][i - 1];
dfs(v);
}
}
int lca(int u, int v) {
if(h[u] < h[v]) swap(u, v);
int diff = h[u] - h[v];
for(int i = 0; i <= LOG; ++i) {
if(diff >> i & 1) u = par[u][i];
}
if(u == v) return u;
for(int i = LOG; i >= 0; --i) {
if(par[u][i] != par[v][i]) {
u = par[u][i];
v = par[v][i];
}
}
return par[u][0];
}
namespace sub1{
bool check() {
return (n <= 1000);
}
void solve() {
long long res = 0;
for(int u = 1; u <= n; ++u) {
for(int v = 1; v <= n; ++v) {
int p = lca(u, v);
long long cost = -w[u];
long long d = h[u] + h[v] - 2*h[p] + 1;
if(d > m) continue;
if(u == v) cost += (nei[u] + w[u]);
else {
long long val1 = dist[u] + dist[v] - 2*dist[p] + w[p] - w[u] - w[v];
long long val2 = totnei[u] + totnei[v] - 2*totnei[p] + nei[p];
assert(val1 <= val2);
cost += (val2 - val1);
}
maximize(res, cost);
}
}
cout << res;
}
}
namespace full{
long long f[MAXN1][103];
long long g[MAXN1][103];
pair<long long, int> M[103][3];
long long res = 0;
void down(int u) {
f[u][1] = nei[u];
for(int v : adj[u]) {
if(v == par[u][0]) continue;
down(v);
for(int i = 1; i <= m; ++i) {
maximize(f[u][i], f[v][i]);
if(i > 1) maximize(f[u][i], f[v][i - 1] + nei[u] - w[v]);
if(i > 1) maximize(f[u][i], f[u][i - 1]);
}
}
// cerr << "\n";
// db(u);
// for(int i = 1; i <= m; ++i) db(f[u][i]);
}
void ins(int x, long long val, int u) {
M[x][2] = make_pair(val, u);
sort(M[x], M[x] + 3, greater<>());
}
void calc(int u) {
maximize(res, f[u][m]);
maximize(res, g[u][m]);
// db(u);
// cerr << '\n';
// for(int i = 1; i <= m; ++i) {
// db(g[u][i]);
// cerr << "\n";
// }
//
// cerr << "\n";
for(int i = 1; i <= m; ++i) {
M[i][0] = M[i][1] = M[i][2] = make_pair(-inf, -1);
}
for(int i = 1; i < m; ++i) {
ins(i, g[u][i], u);
}
for(int v : adj[u]) {
if(v == par[u][0]) continue;
for(int i = 1; i <= m; ++i) {
long long val = f[v][i] + nei[u] - w[v];
ins(i + 1, val, v);
//if(i > 1) ins(i, f[v][i], v);
}
}
for(int v : adj[u]) {
if(v == par[u][0]) continue;
for(int i = 1; i <= m; ++i) {
long long val = nei[v] - w[u];
if(M[i - 1][0].se != v) {
val += M[i - 1][0].fi;
}
else val += M[i - 1][1].fi;
if(M[i][0].se != v) {
maximize(g[v][i], M[i][0].fi);
}
else maximize(g[v][i], M[i][1].fi);
if(i > 1) maximize(g[v][i], g[v][i - 1]);
if(i > 1) maximize(g[v][i], val);
}
}
for(int v : adj[u]) {
if(v != par[u][0]) calc(v);
}
}
void solve() {
down(1);
for(int i = 1; i <= n; ++i) {
g[i][1] = nei[i];
}
calc(1);
cout << res;
}
}
int main() {
fast_cin();
if(ifstream("tomjerry.inp")) {
freopen("tomjerry.inp", "r", stdin);
freopen("tomjerry.out", "w", stdout);
}
cin >> n >> m;
for(int i = 1; i <= n; ++i) cin >> w[i];
for(int i = 1; i < n; ++i) {
int u,v;
cin >> u >> v;
nei[u] += w[v];
nei[v] += w[u];
adj[u].push_back(v);
adj[v].push_back(u);
}
if(m == 0) {
cout << 0 << "\n";
exit(0);
}
dfs(1);
// if(sub1::check()) {
// sub1::solve();
// return 0;
// }
full::solve();
#ifndef LOCAL
cerr << "\nTime elapsed: " << 1.0 * (double)clock() / CLOCKS_PER_SEC << " s.\n ";
#endif
return 0;
}
