import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] p = new int[n];
		for (int i = 0; i < n; i++) {
			p[i] = sc.nextInt() - 1;
		}
		sc.close();

		int[] a = new int[n];
		for (int i = 0; i < n; i++) {
			a[p[i]] = i;
		}

		int ans = 0;
		for (int i = 0; i < n; i++) {
			if (p[i] == i) {
				continue;
			}
			while (p[i] > i) {
				int x = a[p[i] - 1];
				a[p[i] - 1] = i;
				a[p[i]] = x;
				p[i]--;
				p[x]++;
				ans++;
			}
		}
		System.out.println(ans);
	}
}