#include<iostream>
#include<algorithm>
#include<cstdio>
#define LSON rt<<1
#define RSON rt<<1|1
#define DATA(x) b[x].data
#define POS(x) b[x].pos
#define SIGN(x) b[x].c
#define LSIDE(x) b[x].l
#define RSIDE(x) b[x].r
#define WIDTH(x) (RSIDE(x)-LSIDE(x)+1)
#define MAXN 200010
using namespace std;
int n,m,c=1,d=1;
int val[MAXN],head[MAXN],deep[MAXN],son[MAXN],size[MAXN],fa[MAXN],id[MAXN],pos[MAXN],top[MAXN];
long long sum[MAXN];
bool used[MAXN];
struct Tree{
int next,to;
}a[MAXN<<1];
struct Segment_Tree{
long long data,pos,c;
int l,r;
}b[MAXN<<2];
inline int read(){
int date=0,w=1;char c=0;
while(c<‘0‘||c>‘9‘){if(c==‘-‘)w=-1;c=getchar();}
while(c>=‘0‘&&c<=‘9‘){date=date*10+c-‘0‘;c=getchar();}
return date*w;
}
inline void add(int x,int y){
a[c].to=y;a[c].next=head[x];head[x]=c++;
a[c].to=x;a[c].next=head[y];head[y]=c++;
}
void dfs1(int rt){
son[rt]=0;size[rt]=1;
for(int i=head[rt];i;i=a[i].next){
int will=a[i].to;
if(!deep[will]){
deep[will]=deep[rt]+1;
sum[will]=sum[rt]+val[will];
fa[will]=rt;
dfs1(will);
size[rt]+=size[will];
if(size[son[rt]]<size[will])son[rt]=will;
}
}
}
void dfs2(int rt,int f){
id[rt]=d++;pos[id[rt]]=rt;top[rt]=f;
if(son[rt])dfs2(son[rt],f);
for(int i=head[rt];i;i=a[i].next){
int will=a[i].to;
if(will!=fa[rt]&&will!=son[rt])dfs2(will,will);
}
}
inline void pushup(int rt){
DATA(rt)=max(DATA(LSON),DATA(RSON));
if(DATA(LSON)>DATA(RSON))POS(rt)=POS(LSON);
else POS(rt)=POS(RSON);
}
inline void pushdown(int rt){
if(!SIGN(rt)||LSIDE(rt)==RSIDE(rt))return;
SIGN(LSON)+=SIGN(rt);DATA(LSON)+=SIGN(rt);
SIGN(RSON)+=SIGN(rt);DATA(RSON)+=SIGN(rt);
SIGN(rt)=0;
}
void buildtree(int l,int r,int rt){
LSIDE(rt)=l;RSIDE(rt)=r;SIGN(rt)=0;
if(l==r){
DATA(rt)=sum[pos[l]];
POS(rt)=l;
return;
}
int mid=l+r>>1;
buildtree(l,mid,LSON);
buildtree(mid+1,r,RSON);
pushup(rt);
}
void update(int l,int r,long long c,int rt){
if(l<=LSIDE(rt)&&RSIDE(rt)<=r){
SIGN(rt)+=c;DATA(rt)+=c;
return;
}
pushdown(rt);
int mid=LSIDE(rt)+RSIDE(rt)>>1;
if(l<=mid)update(l,r,c,LSON);
if(mid<r)update(l,r,c,RSON);
pushup(rt);
}
long long query(int l,int r,int rt){
long long ans=0;
if(l<=LSIDE(rt)&&RSIDE(rt)<=r)return DATA(rt);
pushdown(rt);
int mid=LSIDE(rt)+RSIDE(rt)>>1;
if(l<=mid)ans=max(ans,query(l,r,LSON));
if(mid<r)ans=max(ans,query(l,r,RSON));
return ans;
}
void work(){
long long ans=0;
for(int i=1;i<=m;i++){
ans+=query(1,n,1);
int x=pos[POS(1)];
while(x&&used[x]){
update(id[x],id[x]+size[x]-1,-val[x],1);
used[x]=false;
x=fa[x];
}
}
printf("%lld\n",ans);
}
void init(){
int x,y;
n=read();m=read();
for(int i=1;i<=n;i++){
val[i]=read();
used[i]=true;
}
for(int i=1;i<n;i++){
x=read();y=read();
add(x,y);
}
deep[1]=1;sum[1]=val[1];
dfs1(1);
dfs2(1,1);
buildtree(1,n,1);
}
int main(){
init();
work();
return 0;
}