MOD = 998244353

n = int(input())
edges = [[] for _ in range(n)]
for i in range(1, n):
    p = int(input()) - 1
    edges[p].append(i)
    
dist = [0] * n
stack = [0]
ans = 1
while stack:
    pos = stack.pop()
    for npos in edges[pos]:
        dist[npos] = dist[pos] + 1
        ans *= dist[npos]
        ans %= MOD
        stack.append(npos)
print(ans)