#include <bits/stdc++.h>
#define _overload3(_1, _2, _3, name, ...) name
#define _rep(i, n) repi(i, 0, n)
#define repi(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define rep(...) _overload3(__VA_ARGS__, repi, _rep, )(__VA_ARGS__)
#define ll long long
#define lld long double
#ifdef DEBUG
#define line() cout << "[" << __LINE__ << "] ";
#define dump(i) cout << #i ": " << i << " ";
#define dumpl(i) cout << #i ": " << i << endl;
#else
#define line(i)
#define dump(i)
#define dumpl(i)
#endif
using namespace std;
ll calc(map<int, vector<int>> &mp, int index, int level)
{
    if (mp[index].empty())
        return level;
    ll ret = 0;
    for (int i : mp[index])
    {
        ret += calc(mp, i, level + 1);
    }
    return ret;
}
int main()
{
    int n;
    cin >> n;
    map<int, vector<int>> mp;
    rep(i, n - 1)
    {
        int t;
        cin >> t;
        mp[t].push_back(i + 1);
    }
    cout << calc(mp, 0, 0) << endl;
    return 0;
}