N = input()
array = [int(x) for x in raw_input().split()]
P = 0
for i in xrange(N):
    for j in xrange(N - 1):
        if array[j] > array[j + 1]:
            z = array[j]
            array[j] = array[j + 1]
            array[j + 1] = z
            P += 1
print P