N, K = map(int, input().split())
A = tuple(map(int, input().split()))
C = tuple(map(int, input().split()))
dp = [[dict() for _ in range(N)] for _ in range(N)]
ans = 0
for i in range(N):
    dp[i][i][C[i]] = A[i]
    ans = max(ans, dp[i][i][C[i]])

for k in range(N-1):
    for i in range(N):
        for c in dp[i][(i+k)%N]:
            for j in range(N):
                for nc in dp[(i+k+1)%N][(i+k+1+j)%N]:
                    if abs(c-nc)<=K:
                        if c not in dp[i][(i+k+1+j)%N]:
                            dp[i][(i+k+1+j)%N][c] = 0
                        dp[i][(i+k+1+j)%N][c] = max(dp[i][(i+k+1+j)%N][c], dp[i][(i+k)%N][c] + dp[(i+k+1)%N][(i+k+1+j)%N][nc])
                        ans = max(ans, dp[i][(i+k+1+j)%N][c])
                        if nc not in dp[i][(i+k+1+j)%N]:
                            dp[i][(i+k+1+j)%N][nc] = 0
                        dp[i][(i+k+1+j)%N][nc] = max(dp[i][(i+k+1+j)%N][nc], dp[i][(i+k)%N][c] + dp[(i+k+1)%N][(i+k+1+j)%N][nc])
                        ans = max(ans, dp[i][(i+k+1+j)%N][nc])
                for nc in dp[(i-1-j)%N][(i-1)%N]:
                    if abs(c-nc)<=K:
                        if c not in dp[(i-1-j)%N][(i+k)%N]:
                            dp[(i-1-j)%N][(i+k)%N][c] = 0
                        dp[(i-1-j)%N][(i+k)%N][c] = max(dp[(i-1-j)%N][(i+k)%N][c], dp[i][(i+k)%N][c] + dp[(i-1-j)%N][(i-1)%N][nc])
                        ans = max(ans, dp[(i-1-j)%N][(i+k)%N][c])
                        if nc not in dp[(i-1-j)%N][(i+k)%N]:
                            dp[(i-1-j)%N][(i+k)%N][nc] = 0
                        dp[(i-1-j)%N][(i+k)%N][nc] = max(dp[(i-1-j)%N][(i+k)%N][nc], dp[i][(i+k)%N][c] + dp[(i-1-j)%N][(i-1)%N][nc])
                        ans = max(ans, dp[(i-1-j)%N][(i+k)%N][nc])

#print(dp)
print(ans)