MOD = 998244353

def main():
    import sys
    sys.setrecursionlimit(1 << 25)
    N = int(sys.stdin.readline())
    if N == 1:
        print(1)
        return
    parent = [0] * (N + 1)  # parent[2] = p_2, etc.
    for i in range(2, N+1):
        parent[i] = int(sys.stdin.readline())
    
    # Compute depth of each node using BFS
    from collections import deque
    depth = [0] * (N + 1)
    visited = [False] * (N + 1)
    q = deque()
    q.append(1)
    visited[1] = True
    depth[1] = 0
    while q:
        u = q.popleft()
        for v in range(2, N+1):
            if parent[v] == u and not visited[v]:
                visited[v] = True
                depth[v] = depth[u] + 1
                q.append(v)
    
    res = 1
    for i in range(2, N+1):
        res = res * depth[i] % MOD
    print(res)

if __name__ == '__main__':
    main()