#include <cassert>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <iomanip>
#include <climits>
#include <map>
#include <queue>
#include <set>
#include <cstring>
#include <vector>

using namespace std;
typedef long long ll;

int main() {
  int N, C;
  cin >> N >> C;
  int L[N];
  int W[N];
  int max_L = 0;

  for (int i = 0; i < N; ++i) {
    cin >> L[i];

    max_L = max(max_L, L[i]);
  }
  for (int i = 0; i < N; ++i) {
    cin >> W[i];
  }

  int dp_up[51][51][51];
  int dp_down[51][51][51];
  memset(dp_up, -1, sizeof(dp_up));
  memset(dp_down, -1, sizeof(dp_down));

  for (int i = 0; i < N; ++i) {
    int l1 = L[i];
    int w1 = W[i];
    if (w1 > C) continue;

    for (int j = 0; j < N; ++j) {
      int l2 = L[j];
      int w2 = W[j];
      int w = w1 + w2;
      if (w > C) continue;
      if (l1 == l2) continue;

      if (l1 < l2) {
        dp_up[w][l1][l2] = l1 + l2;
      } else {
        dp_down[w][l1][l2] = l1 + l2;
      }
    }
  }

  int ans = 0;

  for (int c = 0; c < C; ++c) {
    for (int s1 = 1; s1 <= max_L; ++s1) {
      for (int s2 = 1; s2 <= max_L; ++s2) {
        if (dp_up[c][s1][s2] != -1) {
          for (int i = 0; i < N; ++i) {
            int s3 = L[i];
            int w = W[i];
            int nc = c + w;
            if (s2 <= s3) continue;
            if (s1 == s3) continue;
            if (nc > C) continue;

            dp_down[nc][s2][s3] = max(dp_down[nc][s2][s3], dp_up[c][s1][s2] + s3);
            ans = max(ans, dp_down[nc][s2][s3]);
          }
        }

        if (dp_down[c][s1][s2] != -1) {
          for (int i = 0; i < N; ++i) {
            int s3 = L[i];
            int w = W[i];
            int nc = c + w;
            if (s2 >= s3) continue;
            if (s1 == s3) continue;
            if (nc > C) continue;

            dp_up[nc][s2][s3] = max(dp_up[nc][s2][s3], dp_down[c][s1][s2] + s3);
            // fprintf(stderr, "(%d -> %d): %d\n", s2, s3, dp_down[c][s1][s2] + s3);
            ans = max(ans, dp_up[nc][s2][s3]);
          }
        }
      }
    }
  }

  cout << ans << endl;

  return 0;
}