use strict;
use warnings;

my $n = <>;
my $l = length $n; $l--;
my @num = $n =~ /./g;

my $swp;
my @ans;
for my $i (0..$l-1){
  for my $j ($i+1..$l){
    $swp = $num[$i];
    $num[$i] = $num[$j];
    $num[$j] = $swp;
    push @ans, join('', @num);
    $swp = $num[$i];
    $num[$i] = $num[$j];
    $num[$j] = $swp;
  }
}
print+(sort {$b <=> $a} @ans)[0];