N = gets.chomp
L = N.size

def dfs(sum, mask)
  res = sum

  [*0...L].combination(3).each do |i, j, k|
    next if mask[i] == 1
    next if mask[j] == 1
    next if mask[k] == 1
    next if N[i] == N[j]
    next if N[j] != N[k]
    nmask = mask | (1 << i) | (1 << j) | (1 << k)
    v = (N[i] + N[j] + N[k]).to_i

    val = dfs(sum + v, nmask)
    res = val if res < val
  end

  res
end

puts dfs(0, 0)