#include <bits/stdc++.h>
using namespace std;

int main() {
    int N;
    cin >> N;
    vector<int>R(N-1);
    for(int i = 0; i < N-1; i++) {
        cin >> R[i];
        R[i]--;
    }
    if(R[0] == N-1) {
        cout << 1 << endl;
        return 0;
    }
    int n = 0,cnt = 0;
    while (true) {
        int nxt = n;
        for(int i = n+1; i <= R[n]; i++) {
            if(R[nxt] < R[i]) {
                nxt = i;
            }
        }
        cnt++;
        if(R[nxt] == N-1) {
            cnt++;
            break;
        }
        n = nxt;
    }
    cout << cnt << endl;
}