## https://yukicoder.me/problems/no/778

import sys

sys.setrecursionlimit(201000)

class BinaryIndexTree:
    """
    フェニック木(BinaryIndexTree)の基本的な機能を実装したクラス
    """
    def __init__(self, size):
        self.size = size
        self.array = [0] * (size + 1)
    
    def add(self, x, a):
        index = x
        while index <= self.size:
            self.array[index] += a
            index += index & (-index)
    
    def sum(self, x):
        index = x
        ans = 0
        while index > 0:
            ans += self.array[index]
            index -= index & (-index)
        return ans

    def least_upper_bound(self, value):
        if self.sum(self.size) < value:
            return -1
        elif value <= 0:
            return 0

        m = 1
        while m < self.size:
            m *= 2

        k = 0
        k_sum = 0
        while m > 0:
            k0 = k + m
            if k0 < self.size:
                if k_sum + self.array[k0] < value:
                    k_sum += self.array[k0]
                    k += m
            m //= 2
        if k < self.size:
            return k + 1
        else:
            return -1


def main():
    N = int(input())
    A = list(map(int, input().split()))


    euler_tour = [[-1, -1] for _ in range(N)]
    next_nodes = [[] for _ in range(N)]
    for i, a in enumerate(A):
        next_nodes[a].append(i + 1)

    def dfs(next_nodes, v, euler_index, euler_tour):
        euler_tour[v][0] = euler_index

        euler_index += 1
        for n in next_nodes[v]:
            euler_index = dfs(next_nodes, n, euler_index, euler_tour)
        
        euler_tour[v][1] = euler_index
        euler_index += 1
        return euler_index
    
    euler_index = dfs(next_nodes, 0, 0, euler_tour)
    bit = BinaryIndexTree(euler_index)

    # 番号の大きい順かあ処理
    answer = 0
    for i in reversed(range(N)):
        in_, out_ = euler_tour[i]

        start = bit.sum(in_)
        end = bit.sum(out_)
        child_num = end - start
        answer += child_num

        bit.add(in_ + 1, 1)
    print(answer)











if __name__ == '__main__':
    main()