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