N = gets.to_i
S = N.to_s
A = S.chars
p (0...S.size-1).inject(N){|r, i|
  s = S.dup
  a = A[i + 1..-1]
  j = i + 1 + a.rindex(a.max)
  s[i], s[j] = s[j], s[i]
  [r, s.to_i].max
}