#include<iostream>
using namespace std;

int main() {
    int n; cin >> n;
    int R[n];
    for(int i=0; i<n;i++)cin >>R[i];
    int p=0;
    int ans = 0;
    
    while (R[p] != n) {
        int to = 0;
        for(int i=p; i<R[p];i++) {
            if (to < R[i]) to = R[i];
        }
        ++ans;
        p = to;
    }
    cout << ans << endl;
    
}