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