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

public class Main {
	public static void main (String[] args) throws Exception {
	    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int n = Integer.parseInt(br.readLine());
		int[] arr = new int[n];
		for (int i = 0; i < n; i++) {
		    arr[i] = Integer.parseInt(br.readLine());
		}
		int count = 0;
		for (int i = n - 1; i >= 0; i--) {
		    for (int j = 0; j < i; j++) {
		        if (arr[j] > arr[j + 1]) {
		            count++;
		            //int tmp = arr[j];
		            //arr[j] = arr[j + 1];
		            //arr[j + 1] = tmp;
		        }
		    }
		}
		System.out.println(count);
    }
}