import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		StringBuilder sb = new StringBuilder();
		int n = sc.nextInt();
		int[] a = new int[n];
		for (int i = 0; i < n; i++) {
			a[i] = sc.nextInt();
		}
		int cnt = 0;
		for (int i = n - 1; i >= 0; i--) {
			if (a[i] == n) {
				cnt++;
				n--;
			}
		}
		System.out.println(a.length - cnt);
	}
}