#include<stdio.h>
int main()
{
	int n;
	scanf("%d", &n);
	int i;
	int p[3003];
	for (i = 0; i < n; i++)
	{
		scanf("%d", &p[i]);
		p[i]--;
	}
	int a[3003];
	for (i = 0; i < n; i++)
		a[p[i]] = i;
	int ans = 0;
	for (i = 0; i < n; i++)
	{
		while (p[i] != i)
		{
			ans++;
			a[p[i]] = a[p[i] - 1];
			p[a[p[i] - 1]] = p[i];
			p[i]--;
			a[p[i]] = i;
		}
	}
	printf("%d\n", ans);
	return 0;
}