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
local maxdig = 1
for i = 2, #t do
  if(t[maxdig] < t[i]) then maxdig = i end
end
local reppos = maxdig
for i = #t, maxdig, -1 do
  if(t[i] < t[maxdig]) then reppos = i break end
end
t[reppos], t[maxdig] = t[maxdig], t[reppos]
for i = #t, 1, -1 do
  io.write(t[i])
end
io.write("\n")