/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
    public static void main (String[] args) throws java.lang.Exception
    {
        // your code goes here
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int n = Integer.parseInt(br.readLine());
        String[] lines = br.readLine().split(" ");
        HashMap<Integer,Integer> map = new HashMap<Integer,Integer>();
        int idx = 0;
        for(String st:lines){
            map.put(Integer.parseInt(st),idx++);
        }
        int tmp = n;
        int ans;
        for(ans = n;ans>0;ans--){
            if(map.get(ans) > tmp){
                break;
            }
            tmp = map.get(ans);
        }
        System.out.println(ans);
    }
}