mod=998244353

n=int(input())

a=list(map(int,input().split()))

g=[[]for i in range(n)]

for i in range(n-1):
	u,v=map(int,input().split())
	u-=1
	v-=1
	g[u].append(v)
	g[v].append(u)

ans=0

def dfs(p,prev):
	global ans
	
	sm1=0
	sm2=0

	for e in g[p]:
		if e==prev:continue
		v=dfs(e,p)
		sm1=(sm1+v)%mod
		sm2=(sm2+v*v)%mod
	
	ans=(ans+a[p]*sm1)%mod

	ans=(ans+a[p]*(sm1*sm1-sm2)*pow(2,mod-2,mod))%mod

	return a[p]*(1+sm1)%mod

dfs(0,-1)

print(ans)