#include<iostream>
#include<cstdio>
#include<vector>
#include<algorithm>
#define N 300000
#define mod 998244353
using namespace std;
int read()
{
    char c=0;
    int sum=0;
    while (c<'0'||c>'9') c=getchar();
    while ('0'<=c&&c<='9') sum=sum*10+c-'0',c=getchar();
    return sum;
}
void Adder(int &x,int d)
{
    x+=d;
    if (x>=mod) x-=mod;
    return;
}
void Adder2(int &x,int d)
{
    x+=d;
    if (x<0) x+=mod;
    return;
}
int MD(int x)
{
    return x>=mod?x-mod:x;
}
int MD2(int x)
{
    return x<0?x+mod:x;
}
int fast_pow(int a,int b)
{
    int res=1,mul=a;
    while (b)
    {
	if (b&1) res=1ll*res*mul%mod;
	mul=1ll*mul*mul%mod,b>>=1;
    }
    return res;
}
struct matrix
{
    int d00,d10,d11,d20,d21,d22;
};
matrix c;
matrix operator * (matrix a,matrix b)
{
    c.d00=1;
    c.d10=(a.d10+1ll*a.d11*b.d10)%mod;
    c.d11=1ll*a.d11*b.d11%mod;
    c.d20=(a.d20+1ll*a.d21*b.d10+b.d20)%mod;
    c.d21=(1ll*a.d21*b.d11+b.d21)%mod;
    c.d22=1;
    return c;
}
int n,leng,inv2=(mod+1)>>1,fa[N+1],hs[N+1],top[N+1],bt[N+1],dfn[N+1],rev[N+1],sz[N+1],a[N+1],p[N+1],dp[N+1],DP[N+1],s[N+1],S[N+1],ans;
bool used[N+1],vis[N+1];
vector<int>E[N+1];
void add(int x,int y)
{
    E[x].push_back(y),E[y].push_back(x);
    return;
}
bool cmp(int x,int y)
{
    return a[x]<a[y];
}
void dfs(int x)
{
    used[x]=sz[x]=dp[x]=1;
    for (int i=0;i<E[x].size();++i)
	if (!used[E[x][i]])
	{
	    fa[E[x][i]]=x,dfs(E[x][i]),dp[x]=1ll*dp[x]*(dp[E[x][i]]+1)%mod*inv2%mod,sz[x]+=sz[E[x][i]],Adder(s[x],s[E[x][i]]);
	    if (sz[E[x][i]]>sz[hs[x]]) hs[x]=E[x][i];
	}
    Adder(s[x],dp[x]);
    return;
}
void dfs2(int x)
{
    dfn[x]=++leng,rev[dfn[x]]=x,DP[x]=1;
    if (hs[x]) top[hs[x]]=top[x],dfs2(hs[x]),bt[x]=bt[hs[x]];
    else bt[x]=x;
    for (int i=0;i<E[x].size();++i)
	if (fa[E[x][i]]==x&&E[x][i]!=hs[x])
	    top[E[x][i]]=E[x][i],dfs2(E[x][i]),DP[x]=1ll*DP[x]*(dp[E[x][i]]+1)%mod*inv2%mod,Adder(S[x],s[E[x][i]]);
    if (hs[x]) DP[x]=1ll*DP[x]*inv2%mod;
    return;
}
struct seg
{
    struct node
    {
	int l,r;
	matrix data;
    };
    node tree[(N<<2)+1];
    void push_up(int k)
    {
	tree[k].data=tree[k<<1|1].data*tree[k<<1].data;
	return;    
    }
    void build(int k,int l,int r)
    {
	tree[k].l=l,tree[k].r=r;
	if (l==r)
	{
	    tree[k].data=(matrix){1,DP[rev[l]],DP[rev[l]],MD(DP[rev[l]]+S[rev[l]]),DP[rev[l]],1};
	    return;
	}
	int mid=(l+r)>>1;
	build(k<<1,l,mid),build(k<<1|1,mid+1,r),push_up(k);
	return; 
    }
    void add(int k,int x,matrix d)
    {
	if (tree[k].l==tree[k].r)
	{
	    tree[k].data=d;
	    return;
	}
	int mid=(tree[k].l+tree[k].r)>>1;
	if (x<=mid) add(k<<1,x,d);
	else add(k<<1|1,x,d);
	push_up(k);
	return;
    }
    matrix query(int k,int l,int r)
    {
	if (tree[k].l==l&&tree[k].r==r) return tree[k].data;
	int mid=(tree[k].l+tree[k].r)>>1;
	if (r<=mid) return query(k<<1,l,r);
	else if (l>=mid+1) return query(k<<1|1,l,r);
	else return query(k<<1|1,mid+1,r)*query(k<<1,l,mid);
    }
};
seg T;
void del(int x)
{
    int y;
    matrix rst;
    vis[x]=1;
    while (x)
    {
	if (!vis[x]) T.add(1,dfn[x],(matrix){1,DP[x],DP[x],MD(DP[x]+S[x]),DP[x],1});
	else T.add(1,dfn[x],(matrix){1,0,0,S[x],0,1});
	y=top[x],rst=T.query(1,dfn[y],dfn[bt[y]]);
	if (fa[y]) DP[fa[y]]=1ll*DP[fa[y]]*fast_pow(MD(dp[y]+1),mod-2)%mod,Adder2(S[fa[y]],-s[y]);
	s[y]=rst.d20,dp[y]=rst.d21;
	if (fa[y]) DP[fa[y]]=1ll*DP[fa[y]]*MD(dp[y]+1)%mod,Adder(S[fa[y]],s[y]);
	x=fa[y];
    }
    return;
}
int main()
{
    int x,y;
    n=read();
    for (int i=1;i<=n;++i) a[i]=read(),p[i]=i;
    sort(p+1,p+n+1,cmp);
    for (int i=1;i<=n-1;++i) x=read(),y=read(),add(x,y);
    dfs(1),top[1]=1,dfs2(1),T.build(1,1,n);
    Adder(ans,1ll*MD(s[1]+dp[1])*inv2%mod*a[p[1]]%mod);
    for (int i=1;i<=n-1;++i) del(p[i]),Adder(ans,1ll*MD(s[1]+dp[1])*inv2%mod*MD2(a[p[i+1]]-a[p[i]])%mod);
    for (int i=1;i<=n-1;++i) ans=2ll*ans%mod;
    printf("%d\n",ans);
    return 0;
}