✅ 정답 공개
n, m = map(int, input().split())
heights = list(map(int, input().split()))
left, right = 0, max(heights)
result = 0
while left <= right:
mid = (left + right) // 2
total = sum(max(0, h - mid) for h in heights)
if total >= m:
result = mid
left = mid + 1
else:
right = mid - 1
print(result)