#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ii pair<ll,ll>
#define fi first
#define se second
#define endl '\n'
#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define rep(x,s,e) for (auto x=s-(s>e);x!=e-(s>e);(s<e?x++:x--))
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)(x).size()
int n,k;
ll arr[100005];
vector<int> al[100005];
ll adj[100005];
ll w1[100005][105]; //asc
ll w2[100005][105]; //dsc
ll ans=0;
void dfs(int i,int p){
ll temp1[105];
ll temp2[105];
ll temp3[105];
memset(temp1,0,sizeof(temp1));
memset(temp2,0,sizeof(temp2));
memset(temp3,0,sizeof(temp3));
for (auto &it:al[i]){
if (it==p) continue;
dfs(it,i);
rep(x,0,k){ //combine 2 and this is taken
ans=max(ans,temp1[k-x-1]+w2[it][x]+adj[i]-arr[it]);
ans=max(ans,w1[it][x]+temp2[k-x-1]+adj[i]);
}
rep(x,0,k){
ans=max(ans,temp1[k-x]+w2[it][x]);
ans=max(ans,w1[it][x]+temp3[k-x]);
}
rep(x,0,k){
ans=max(ans,w1[it][x]+adj[i]);
w1[i][x]=max(w1[i][x],w1[it][x]);
if (p!=-1) w1[i][x+1]=max(w1[i][x+1],w1[it][x]+adj[i]-arr[p]);
temp1[x]=max(temp1[x],w1[it][x]);
}
rep(x,0,k){
ans=max(ans,w2[it][x]+adj[i]-arr[it]);
w2[i][x]=max(w2[i][x],w2[it][x]);
w2[i][x+1]=max(w2[i][x+1],w2[it][x]+adj[i]-arr[it]);
temp2[x]=max(temp2[x],w2[it][x]-arr[it]);
temp3[x]=max(temp3[x],w2[it][x]);
}
}
rep(x,1,k) w2[i][x]=max(w2[i][x],adj[i]);
//cout<<"ans: "<<i<<" "<<ans<<endl;
//cout<<i<<": "<<endl;
//rep(x,0,k) cout<<w1[i][x]<<" "; cout<<endl;
//rep(x,0,k) cout<<w2[i][x]<<" "; cout<<endl;
}
int main(){
cin.tie(0);
cout.tie(0);
cin.sync_with_stdio(false);
cin>>n>>k;
rep(x,1,n+1) cin>>arr[x];
int a,b;
rep(x,1,n){
cin>>a>>b;
al[a].pub(b);
al[b].pub(a);
adj[a]+=arr[b];
adj[b]+=arr[a];
}
/*
dfs(4,-1);
cout<<ans<<endl;
return 0;
*/
dfs(1,-1);
cout<<ans<<endl;
}
