local orig = io.read("*n")
local t = {}
while(0 < orig) do
  local a = orig % 10
  table.insert(t, a)
  orig = math.floor(orig / 10)
end
for j = #t, 1, -1 do
  local maxdig = 1
  for i = 2, j do
    if(t[maxdig] < t[i]) then maxdig = i end
  end
  if(t[j] < t[maxdig]) then
    t[j], t[maxdig] = t[maxdig], t[j]
    break
  end
end
for i = #t, 1, -1 do
  io.write(t[i])
end
io.write("\n")