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
    for ak in ad.keys():
        res = max(res, abs(ad[ak] - tl[ak]))
    print(res)

if __name__=="__main__":
    solve()