#include<bits/stdc++.h>
#define ll long long
#define inf 1e9
#define rep(i,l,r) for(register int i=l;i<=r;++i)
#define per(i,r,l) for(register int i=r;i>=l;--i)
using namespace std;
const int N=1010,Mod=998244353; 

struct SGT{
	int maxx,minn;
}sgt[N<<2];
struct edge{
	int nxt,to;
}e[N<<1];
int head[N],num;
int n;
int siz[N],res[N],dep[N],son[N];
int w[N],wx[N],idx[N],top[N],cnt;
ll ans;
inline void add(int from,int to){
	e[++num].nxt=head[from];
	e[num].to=to;
	head[from]=num;
} 
inline void dfs1(int u,int fa){
	siz[u]=fa;
	res[u]=fa;
	dep[u]=dep[fa]+1;
	for(int i=head[u];i;i=e[i].nxt){
		int v=e[i].to;
		if(v==fa)continue;
		dfs1(v,u);
		siz[u]+=siz[v];
		if(siz[v]>siz[son[u]])son[u]=v;
	}
}
inline void dfs2(int u,int topf){
	idx[u]=++cnt;
	wx[cnt]=w[u];
	top[u]=topf;
	if(!son[u])return;
	dfs2(son[u],topf);
	for(int i=head[u];i;i=e[i].nxt){
		int v=e[i].to;
		if(v==res[u]||v==son[u])continue;
		dfs2(v,v);
	}
}
inline void pushup(int p){
	sgt[p].maxx=max(sgt[p<<1].maxx,sgt[p<<1|1].maxx);
	sgt[p].minn=min(sgt[p<<1].minn,sgt[p<<1|1].minn);
}
inline void build(int p,int l,int r){
	if(l==r){
		sgt[p].maxx=sgt[p].minn=wx[l];
		return;
	}
	int mid=l+r>>1;
	build(p<<1,l,mid);
	build(p<<1|1,mid+1,r);
	pushup(p);
}
inline int query_max(int p,int l,int r,int x,int y){
	if(l>=x&&r<=y)return sgt[p].maxx;
	int ret=0;
	int mid=l+r>>1;
	if(x<=mid)ret=max(ret,query_max(p<<1,l,mid,x,y));
	if(y>mid)ret=max(ret,query_max(p<<1|1,mid+1,r,x,y));
	return ret;
}
inline int query_min(int p,int l,int r,int x,int y){
	if(l>=x&&r<=y)return sgt[p].minn;
	int ret=inf;
	int mid=l+r>>1;
	if(x<=mid)ret=min(ret,query_min(p<<1,l,mid,x,y));
	if(y>mid)ret=min(ret,query_min(p<<1|1,mid+1,r,x,y));
	return ret;
}
inline int ask(int x,int y){
	int maxx=0,minn=inf;
	while (top[x]!=top[y]){
		if(dep[top[x]]<dep[top[y]])swap(x,y);
		maxx=max(maxx,query_max(1,1,n,idx[top[x]],idx[x]));
		minn=min(minn,query_min(1,1,n,idx[top[x]],idx[x]));
		x=res[top[x]];
	}
	if(dep[x]>dep[y])swap(x,y);
	maxx=max(maxx,query_max(1,1,n,idx[x],idx[y]));
	minn=min(minn,query_min(1,1,n,idx[x],idx[y]));
	return maxx*minn%Mod;
}
int main(){
	scanf("%d",&n);
	rep(i,1,n)scanf("%d",&w[i]);
	rep(i,1,n-1){
		int x,y;
		scanf("%d%d",&x,&y);
		add(x,y);
		add(y,x);
	}
	dfs1(1,0);
	dfs2(1,1);
	//rep(i,1,n)cout<<idx[i]<<' ';cout<<endl;
	build(1,1,n);
	//cout<<query_max(1,1,n,1,2)<<endl;
	//cout<<ask(idx[1],idx[3])<<endl;
	rep(i,1,n)
	    rep(j,i,n)
	        ans+=ask(i,j),ans%=Mod;
	printf("%lld\n",ans);
	return 0;
}