function lps(seq : string; i,

function lps(seq : string; i, j : longint) : longint;
var
  len1, len2 : longint;
begin
  if i = j then
    exit(1);
  if i > j then
    exit(0);
  if (seq[i] = seq[j]) then
    exit(lps(seq, i + 1, j - 1) + 2);
  len1 := lps(seq, i, j - 1);
  len2 := lps(seq, i + 1, j);
  if len1 > len2 then
    exit(len1)
  else
    exit(len2);
end;
var
  n : longint;
  seq : string;
begin
  seq := 'acmerandacm';
  n := length(seq);
  writeln(lps(seq, 1, n));
end.