def solve(): al, tl = [], [] n = int(input()) for j in input().split(): i = int(j) al.append(i) tl.append(i) ad = dict(zip(al, [i for i in range(n)])) tl = dict(zip(sorted(tl), [i for i in range(n)])) res = 0 rsum = 0 for ak in ad.keys(): t = ad[ak] - tl[ak] res = max(res, abs(t)) rsum = t print(max(res, rsum)) if __name__=="__main__": solve()