# (ΦωΦ)＜これはいい問題だ！
var
  n = stdin.readLine

proc conv(c: char): int = result = int(c) - int('0')

block away:
  for i in 0.. n.high:
    var ha = conv(n[i+1])
    for j in i+1.. n.high: ha = max(ha, conv(n[j]))
    if conv(n[i]) >= ha: continue
    for j in countdown(n.high, i+1):
      if ha == conv(n[j]):
        swap n[i], n[j]
        break away
echo n