n, k = map(int,input().split())
item = list(map(float,input().split()))

def check(mid):
    total = 0
    for i in range(len(item)):
        total += item[i] / mid
    return total >= k

ans = 0
left, right = 0, max(item)
while left <= right:
    mid = (left + right) // 2
    if mid == 0:
        break
    if check(mid):
        # ans = mid
        left = mid + 1
        ans = mid
    else:
        right = mid - 1

print('{:.2f}'.format(ans))