n = int(input())
p = list(map(int, input().split()))
a = [0] * n
for i in range(n):
    a[p[i] - 1] = i
a.reverse()
ans = 0
t = n * (n + 1) // 2
for i in range(n):
    ans = max(ans, t - (a[i] + 1) * 2)
    t -= (a[i] + 1)
print(ans)