N, M = map(int, input().split())
A = list(map(int, input().split()))
A.sort(reverse=True)
dp0 = [[0] * (M + 1) for i in range(N + 1)]
dp1 = [[0] * (M + 1) for i in range(N + 1)]
for i in range(1, N):
    for m in range(M + 1):
        dp0[i][m] = max(dp0[i - 1][m], dp1[i - 1][m])
        if i >= 1:
            d = A[i - 1] - A[i]
            if m - d >= 0:
                dp1[i][m] = max(dp1[i][m], dp0[i - 1][m - d] + A[i - 1])
        if i >= 2:
            d = A[i - 2] - A[i]
            if m - d >= 0:
                dp1[i][m] = max(dp1[i][m], dp0[i - 2][m - d] + A[i - 2])

ans = 0
for i in range(N + 1):
    for m in range(M + 1):
        ans = max(ans, dp0[i][m], dp1[i][m])
print(ans)