"""

想定解 v3
バブルソートバージョン

"""

import sys
from sys import stdin

N = int(stdin.readline())

A = list(map(int,stdin.readline().split()))

assert 2 <= N <= 3000

B = [A[i] for i in range(N)]
B.sort()
for i in range(N):
    assert B[i] == i+1

C = [None] * N
for i in range(N):
    C[A[i]-1] = i

#print (C)

ans = 0

for i in range(N):
    for j in range(N-1,i,-1):

        if C[j-1] > C[j]:
            C[j-1],C[j] = C[j],C[j-1]
            ans += 1

print (ans)