N = int(input())
P = list(map(int, input().split()))
Q = [0] * N
for i, p in enumerate(P):
    Q[P[i] - 1] = i + 1
sum0 = N * (N + 1) // 2
ans = 0
for i in reversed(range(N)):
    ans = max(ans, sum0 - 2 * Q[i])
    sum0 -= Q[i]
print(ans)