#!/usr/bin/env python3
# %%
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines


# %%
N, *A = map(int, read().split())

# %%
graph = [[] for _ in range(N + 1)]
for i, x in enumerate(A, 2):
    x += 1
    graph[i].append(x)
    graph[x].append(i)


# %%
class BinaryIndexedTree():
    def __init__(self, seq):
        self.size = len(seq)
        self.depth = self.size.bit_length()
        self.build(seq)

    def build(self, seq):
        data = seq
        size = self.size
        for i, x in enumerate(data):
            j = i + (i & (-i))
            if j < size:
                data[j] += data[i]
        self.data = data

    def __repr__(self):
        return self.data.__repr__()

    def get_sum(self, i):
        data = self.data
        s = 0
        while i:
            s += data[i]
            i -= i & -i
        return s

    def add(self, i, x):
        data = self.data
        size = self.size
        while i < size:
            data[i] += x
            i += i & -i

    def find_kth_element(self, k):
        data = self.data
        size = self.size
        x, sx = 0, 0
        dx = 1 << (self.depth)
        for i in range(self.depth - 1, -1, -1):
            dx = (1 << i)
            if x + dx >= size:
                continue
            y = x + dx
            sy = sx + data[y]
            if sy < k:
                x, sx = y, sy
        return x + 1


# # %%
par = [0] * (N + 1)
st = [1]
answer = 0
bit = BinaryIndexedTree([0] * (N + 1))
get_sum = bit.get_sum
add = bit.add
while st:
    x = st[-1]
    if not graph[x]:
        answer += get_sum(x)
        add(x, -1)
        st.pop()
        continue
    y = graph[x].pop()
    if y == par[x]:
        continue
    par[y] = x
    add(y, 1)
    st.append(y)


# %%
print(answer)