def sort(data):
    cnt = 0
    for i in range(len(data)):
        for j in range(len(data) - i - 1):
            if data[j] > data[j+1]:
                data[j], data[j+1] = data[j+1], data[j]
                cnt += 1

    return cnt
                
n = int(input())
p = list(map(int, input().split()))

print(sort(p))