a = int(input())
b=list(map(int,input().split()))
d = 0
for i in range(a-1):
    for j in range(a-1-i):
        if b[j] < b[j+1]:
            c = b[j+1]
            b[j+1] = b[j]
            b[j] = c
        else:
            d += 1
print(d)