import sys
sys.setrecursionlimit(10**7)

def dfs(a, c):
    n = len(a)
    if n==1:
        return max(a)
    ret = max(a)
    for i in range(n):
        if abs(c[i]-c[(i+1)%n])<=K:
            na = []
            nc = []
            idx = -1
            for j in range(n):
                if j==i:
                    idx = len(nc)
                    na.append(a[i]+a[(i+1)%n])
                    nc.append(c[i])
                elif j==(i+1)%n:
                    pass
                else:
                    na.append(a[j])
                    nc.append(c[j])
            ret1 = dfs(na, nc)
            ret = max(ret, ret1)
            nc[idx] = c[(i+1)%n]
            ret2 = dfs(na, nc)
            ret = max(ret, ret2)
    return ret

N, K = map(int, input().split())
A = list(map(int, input().split()))
C = list(map(int, input().split()))

ans = dfs(A, C)
print(ans)