program longestSeqPalindrom;

type stringArray = array [1..100] of string;

var
  noValues : integer;
  values : stringArray;
  start : integer;
  len : integer;



procedure readData(var n : integer; var v : stringArray);
   //reads a vector of strings
   //data: - (reading subalgorithm)
   //results: a vector of strings and its length
   var i : integer;
   begin
        write('no of elements, n = ');
        readln(n);
        for i := 1 to n do
            begin
                 write('element from position ', i, ' is: ');
                 readln(v[i]);
            end;
   end;

procedure printData(n : integer; v : stringArray; start : integer; len : integer);
   //prints a vector of integers
   //data: a vector of strings and its length
   //res: - (printing subalgorithm)
   var i : integer;
   begin
        write('longest sequence of palindrom words is: ');
        for i := start to start + len - 1 do
            write(v[i], ' ');
   end;

function isPalindrom(s : string) : boolean;
        //checks if a string is palindrom or not
	//data: a string
	//res: true, if the string is palindrom
	//     false, otherwise

        var ok : boolean;
            i : integer;
   begin
        ok := true;
        i := 1;
        while ((i <= length(s)/2) and (ok = true)) do
              begin
                   if (s[i] <> s[ length(s) - i + 1]) then ok := false
                   else i := i + 1;
              end;
        isPalindrom := ok;
   end;

function aSequence(n : integer; v : stringArray; start : integer) : integer;
   //search a sequence of prime numbers that start on position
   //start in vector of integer v
   //data: a vector and its length and a start position
   //res: the length of the identified sequence of prime numbers
   var l : integer ;
       i : integer;
   begin
        l := 1;
        i := start + 1;
        while ((i <= n) and (isPalindrom(v[i]) = true)) do
              begin
                   i := i + 1;
                   l := l + 1;
              end;
        aSequence := l;
   end;
procedure longestSeq(n : integer; v : stringArray; var start : integer; var len : integer);
   //identify the longest seq of prime numbers
   //data: a vector of integers and its length
   //res: the longest seq o prime numbers
   var i : integer;
       crtLength : integer;
   begin
        i := 1;
        len := 0;
        while ( i <= n) do
              begin
                   if (isPalindrom(v[i]) = true) then
                      crtLength := aSequence(n, v, i)
                   else
                      crtLength := 0;
                   if (crtLength > len) then
                      begin
                        len := crtLength;
                        start := i;
                        i := i + len - 1;
                      end
                   else
		       if (crtLength > 0) then i:= i + crtLength - 1
		       else i := i + 1;
              end;

   end;

begin
   start := 0;
   len := 0;
   readData(noValues, values);
   longestSeq(noValues, values, start, len);
   printData(noValues, values, start, len);
   readln();
end.