import sys
input = sys.stdin.readline
N = int(input())
a = list(map(int, input().split()))
table = [0] * N
for i in range(N): table[a[i] - 1] = i

res = 0
for _ in range(10000):
  for i in range(N):
    if i - 1 in range(N) and table[i - 1] > table[i]:
      table[i - 1], table[i] = table[i], table[i - 1]
      res += 1
    if i + 1 in range(N) and table[i + 1] < table[i]:
      table[i + 1], table[i] = table[i], table[i + 1]
      res += 1
print(res)