var s:array[1..20] of string;
     n,i,max:integer;
function palindrom(x:string):boolean;
var c,p:string;
begin
palindrom:=false;
p:=x;
c:='';
while p<>'' do begin
               c:=c+copy(p,length(p),1);
               delete(p,length(p),1);
               end;
if c=x then palindrom:=true;
end;
begin
write('n=');readln(n);
for i:=1 to n do begin
                 write('s[',i,']=');
                 readln(s[i]);
                 end;
for i:=1 to n do
    if palindrom(s[i]) then begin
                            max:=length(s[i]);
                            break;
                            end;
for i:=1 to n do
   if palindrom(s[i]) then
           if length(s[i])>max then max:=length(s[i]);
writeln('maximul este',max);
for i:=1 to n do
for i:=1 to n do
   if (palindrom(s[i])) and (length(s[i])=max) then writeln(s[i],' ');
readln;
end.