#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <set>
#include <queue>
#include <string>
#include <iomanip>
using namespace std;

#define ll long long int
#define tlll tuple<ll,ll,ll>
#define pii pair<ll,ll>

tlll params[200];

int main()
{
    int n;
    cin >> n;
    vector<int> vs(n);
    for(int i = 0;i < n;i++)
    {
        cin >> vs[i];
    }
    int current = n + 1;
    int remove = 0;
    for(int i = n-1;i >= 0;i--)
    {
        if(vs[i] == current -1)
        {
            current = vs[i];
            remove++;
        }
    }
    cout << n - remove << endl;
    return 0;
}