n = int(input()) i = 0 j = 0 a = [] add = 0 middle = 0 a = input().split() for i in range(0,n): for j in range(0,n-1-i): if int(a[j+1]) < int(a[j]): a[j+1],a[j]=a[j],a[j+1] add += 1 print(add)