#int-input
def II() -> int : return int(input())
def MI() -> int : return map(int, input().split())



class fenwick_tree():
    n=1
    data=[0 for i in range(n)]
    def __init__(self,N):
        self.n=N
        self.data=[0 for i in range(N)]
    def add(self,p,x):
        assert 0<=p<self.n,"0<=p<n,p={0},n={1}".format(p,self.n)
        p+=1
        while(p<=self.n):
            self.data[p-1]+=x
            p+=p& -p
    def sum(self,l,r):
        assert (0<=l and l<=r and r<=self.n),"0<=l<=r<=n,l={0},r={1},n={2}".format(l,r,self.n)
        return self.sum0(r)-self.sum0(l)
    def sum0(self,r):
        s=0
        while(r>0):
            s+=self.data[r-1]
            r-=r&-r
        return s
class dsu():
    n=1
    parent_or_size=[-1 for i in range(n)]
    def __init__(self,N):
        self.n=N
        self.parent_or_size=[-1 for i in range(N)]
    def merge(self,a,b):
        assert 0<=a<self.n, "0<=a<n,a={0},n={1}".format(a,self.n)
        assert 0<=b<self.n, "0<=b<n,b={0},n={1}".format(b,self.n)
        x=self.leader(a)
        y=self.leader(b)
        if x==y:
            return x
        if (-self.parent_or_size[x]<-self.parent_or_size[y]):
            x,y=y,x
        self.parent_or_size[x]+=self.parent_or_size[y]
        self.parent_or_size[y]=x
        return x
    def same(self,a,b):
        assert 0<=a<self.n, "0<=a<n,a={0},n={1}".format(a,self.n)
        assert 0<=b<self.n, "0<=b<n,b={0},n={1}".format(b,self.n)
        return self.leader(a)==self.leader(b)
    def leader(self,a):
        assert 0<=a<self.n, "0<=a<n,a={0},n={1}".format(a,self.n)
        if (self.parent_or_size[a]<0):
            return a
        self.parent_or_size[a]=self.leader(self.parent_or_size[a])
        return self.parent_or_size[a]
    def size(self,a):
        assert 0<=a<self.n, "0<=a<n,a={0},n={1}".format(a,self.n)
        return -self.parent_or_size[self.leader(a)]
    def groups(self):
        leader_buf=[0 for i in range(self.n)]
        group_size=[0 for i in range(self.n)]
        for i in range(self.n):
            leader_buf[i]=self.leader(i)
            group_size[leader_buf[i]]+=1
        result=[[] for i in range(self.n)]
        for i in range(self.n):
            result[leader_buf[i]].append(i)
        result2=[]
        for i in range(self.n):
            if len(result[i])>0:
                result2.append(result[i])
        return result2

n = II()
a = list(MI())

edge = [set() for i in range(n)]
for i in range(n-1):
    u,v = MI()
    u -= 1
    v -= 1
    edge[u].add(v)
    edge[v].add(u)



mod = 998244353
def DFS_par(edge): #親の情報をうまく持つDFS
    ans = 0
    cnt = [0]*len(edge)
    #親を持ちながら非再帰DFS
    n = len(edge)
    st = [(0,None,0)]
    while st:
        # print(cnt)
        now,par,t = st.pop()
        if t == 0:
            st.append((now,par,1))
            #行きがけ
            for chi in edge[now]:
                if chi != par:
                    st.append((chi,now,0))
        else:
            ans += cnt[now]*a[now]%mod
            if par != None:
                tmp = a[now]*(cnt[now]+1)%mod
                ans += cnt[par]*a[par]*tmp%mod
                cnt[par] += tmp
                
            
            pass
            #帰りがけ
    
    return ans

print(DFS_par(edge)%mod)