#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
#include <queue>
#include <map>
#include <cmath>
#include <iomanip>
#include <set>
#include <cstdio>
#include <string>

using namespace std;

int main() {
  int n;
  cin >> n;
  vector<int> a(n);
  for (int i = 0; i < n - 1; i++) {
    cin >> a[i];
  }
  int j = 0;
  int cnt = 0;
  while (a[j] != n) {
    j = max_element(a.begin() + j, a.begin() + a[j]) - a.begin();
    cnt++;
  }
  cout << cnt + 1 << endl;
  return 0;
}