n = int(input())
p = list(map(int, input().split()))
ans = 0
while True:
    if p == sorted(p): break
    for i in range(1, n):
        a, b = p.index(i), p.index(i + 1)
        if a > b: p[a], p[b] = p[b], p[a]; ans += 1
print(ans)