use strict;
use warnings;

my $line = <>; chomp $line;
unless (length $line) {
  print 0;
  exit;
}

my @arr = split //,$line;
my $max = 0;
for (my $cent = 0; $cent < scalar @arr; $cent++) {
  my $count = 1;
  for (my $i = 1; ; $i++) {
    my $left = $cent - $i;
    my $right = $cent + $i;
    last if $left < 0;
    last if $right >= scalar @arr;
    $count++ if $arr[$left] eq $arr[$right];
  }
  $max = $count if $max < $count;

  $count = 0;
  for (my $i = 1; ; $i++) {
    my $left = $cent;
    my $right = $cent + $i;
    last if $left < 0;
    last if $right >= scalar @arr;
    $count++ if $arr[$left] eq $arr[$right];
  }
  $max = $count if $max < $count;
}

print $max;