#include<bits/stdc++.h>
using namespace std;
using LL=long long;
#define FOR(i,l,r) for(int i=(l);i<=(r);++i)
#define REP(i,n) FOR(i,0,(n)-1)
#define ssize(x) int(x.size())
template<class A,class B>auto&operator<<(ostream&o,pair<A,B>p){return o<<'('<<p.first<<", "<<p.second<<')';}
template<class T>auto operator<<(ostream&o,T x)->decltype(x.end(),o){o<<'{';int i=0;for(auto e:x)o<<(", ")+2*!i++<<e;return o<<'}';}
#ifdef DEBUG
#define debug(x...) cerr<<"["#x"]: ",[](auto...$){((cerr<<$<<"; "),...);}(x),cerr<<'\n'
#else
#define debug(...) {}
#endif
int main() {
cin.tie(0)->sync_with_stdio(0);
int n, V;
cin >> n >> V;
if (V == 0) {
cout << 0 << '\n';
return 0;
}
vector<int> P(n);
REP(i, n)
cin >> P[i];
vector<vector<int>> graph(n);
vector<LL> sum_neighbours(n);
REP(i, n - 1) {
int a, b;
cin >> a >> b;
--a, --b;
graph[a].emplace_back(b);
graph[b].emplace_back(a);
sum_neighbours[a] += P[b];
sum_neighbours[b] += P[a];
}
debug(n, V, P, graph, sum_neighbours);
#ifdef LOCAL
const LL INF = 100;
#else
const LL INF = 1e18;
#endif
using Info = vector<array<LL, 2>>;
Info blank(V + 1);
FOR(i, 0, V) {
blank[i][0] = blank[i][1] = 0;
}
blank[0][1] = -INF;
auto make_info = [&](int v) {
Info ret = blank;
ret[1][1] = sum_neighbours[v];
return ret;
};
auto extend_info = [&](const Info& h, int v) -> Info {
Info ret = blank;
FOR(i, 0, V) {
ret[i][0] = max(h[i][0], h[i][1] - P[v]);
}
FOR(i, 1, V) {
ret[i][1] = ret[i - 1][0] + sum_neighbours[v];
}
debug(h, v, P[v], ret);
return ret;
};
auto get_better = [&](Info a, const Info& b) {
FOR(i, 0, V)
REP(j, 2)
a[i][j] = max(a[i][j], b[i][j]);
return a;
};
auto get_ans = [&](const Info& a) {
LL ans = 0;
FOR(i, 0, V)
REP(j, 2)
ans = max(ans, a[i][j]);
return ans;
};
vector<Info> best(n);
function<void(int, int)> init_dfs = [&](int v, int p) {
auto it = find(graph[v].begin(), graph[v].end(), p);
if (it != graph[v].end())
graph[v].erase(it);
debug(v, p, graph[v]);
for (auto x : graph[v])
init_dfs(x, v);
auto val = make_info(v);
for (int x : graph[v]) {
val = get_better(val, extend_info(best[x], v));
}
best[v] = val;
};
init_dfs(0, -1);
LL ans = 0;
function<void(int, const Info&)> dfs = [&](int v, const Info& value_from_parent) {
const int s = ssize(graph[v]);
vector<Info> values_for_children;
{
const auto extended_value_from_parent = extend_info(value_from_parent, v);
ans = max(ans, get_ans(get_better(extended_value_from_parent, best[v])));
values_for_children.resize(s, extended_value_from_parent);
}
{
auto val = make_info(v);
REP(i, s) {
values_for_children[i] = get_better(values_for_children[i], val);
const int x = graph[v][i];
val = get_better(move(val), extend_info(best[x], v));
}
}
{
auto val = make_info(v);
for (int i = s - 1; i >= 0; --i) {
values_for_children[i] = get_better(values_for_children[i], val);
const int x = graph[v][i];
val = get_better(move(val), extend_info(best[x], v));
}
}
REP(i, ssize(graph[v]))
dfs(graph[v][i], move(values_for_children[i]));
};
dfs(0, blank);
cout << ans << '\n';
#ifdef LOCAL
system("grep VmPeak /proc/$PPID/status >&2");
#endif
}
