import sys
sys.setrecursionlimit(200050)

MOD = 998244353
N = int(input())
A = list(map(int, input().split()))
UV = [list(map(int, input().split())) for _ in range(N - 1)]
E = [[] for _ in range(N)]
for u, v in UV:
    u -= 1
    v -= 1
    E[u].append(v)
    E[v].append(u)

def dfs(x, p):
    global ans, X
    for y in E[x]:
        if y != p:
            X[y] += (X[x] + Y[x] + A[x]) * A[y]
            X[y] %= MOD
            dfs(y, x)
            Y[x] += (Y[y]+ A[y]) * A[x]
            Y[x] %= MOD
    #print(x,X,Y)

X = [0] * N
Y = [0] * N
ans = 0
dfs(0, -1)
#print(X,sum(X))
#print(Y,sum(Y))
print(sum(X) % MOD)