codeforces mafia game

def satisfyeverybody(k,rounds):
    #we play k rounds, then the person i can play i rounds.Then he can supervise k-i(rounds)
    #total supervisor position sum(k-rounds[i]) over all i
    supervisors = sum(map(lambda x: k - x, rounds))
    return supervisors >= k

def minimum_rounds():
    n=int(input())
    rounds=list(map(int,input().strip().split()))

    if len(rounds)<=1:
        return 0
    lower_bound=0
    upper_bound=sum(rounds)
    answer=sum(rounds)
    while lower_bound<=upper_bound:
        mid=(lower_bound+upper_bound)//2
        if (satisfyeverybody(mid,rounds)):
            answer=mid
            upper_bound=mid-1
        else:
            lower_bound=mid+1
    return answer

print(minimumMafiaRounds())