import java.util.Scanner;
public class ccc5s2 {
	public static void main(String[] args) {
		Scanner sc= new Scanner(System.in);
		//		compare with neighbor and see if A[i]<A[i+1]
		//			2 1 3
		//			2 3 1
		//			3 2 1
		int count = 0;
		int N = sc.nextInt();
		int[] A = new int[N];
		while (true) {  //repeat multiple times
			boolean isSwap = false;  //never swap yet
			for (int i=1; i<N; i++)	 {
				if (A[i-1]<A[i]) {
					//swap
					int temp = A[i];
					A[i] = A[i-1];
					A[i-1] = temp;
					count++;
					isSwap = true;
				}
			}
			if (isSwap==false) {
				break;
			}
		}
	}
}