from collections import deque

n, h = map(int, input().split())
a = list(map(int, input().split()))
b = list(map(int, input().split()))

maxv = 0
q = deque()
curr_tired = 0
satisfaction = 0  

for i in range(n):
    q.append((a[i], b[i]))
    satisfaction += a[i]
    curr_tired += b[i]

    tired = sum((j + 1) * item[1] for j, item in enumerate(q))

    while tired > h and q:
        removed = q.popleft()
        satisfaction -= removed[0]
        curr_tired -= removed[1]
        tired = sum((j + 1) * item[1] for j, item in enumerate(q)) 

    maxv = max(maxv, satisfaction)

print(maxv)