import java.util.*;

public class Main {
	public static void main (String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] arr = new int[n + 1];
		for (int i = 0; i < n; i++) {
		    int x = sc.nextInt();
		    arr[x] = i;
		}
		int max = n - 1;
		for (int i = n; i > 1; i--) {
		    if (arr[i] > arr[i - 1]) {
		        max--;
		    } else {
		        break;
		    }
		}
	    System.out.println(max);
	}
}