def check(m):
    cnt = 0
    for i in range(N):
        if m * M > A[i] + cnt:
            return False
        cnt += A[i] - m * M
        if cnt < 0:
            return False
    return True

N, M = map(int, input().split())
A = list(map(int, input().split()))
yes = 0
no = 10 ** 18
while no - yes != 1:
    mid = (yes + no)//2
    if check(mid):
        yes = mid
    else:
        no = mid
print(yes)