Составить палиндром наибольшей длины - C (СИ)

var
 i, n : integer;
         c : char;
  symb : array['A'..'Z'] of longint;
begin
   for c := 'A' to 'Z' do 
       symb[c] := 0;
   readln(n);
   for i := 1 to n do begin
      read(c);
  inc(symb[c]); 
  end;
  for c := 'A' to 'Z' do
    for i := 1 to symb[c] div 2 do
      write(c); 
 for c := 'A' to 'Z' do
 if symb[c] mod 2 = 1 then begin 
           write(c); 
         break; 
  end;
  for c := 'Z' downto 'A' do 
    for i := 1 to symb[c] div 2 do
      write(c); 
end.