#include <fstream>
#include <algorithm>
#include <cstring>
#include <vector>

#define DIM 3100000
#define MAXINDEX 30
#define ERROR_MESSAGE "0"
#define infile "lampa.in"
#define outfile "lampa.out"

using namespace std;

ifstream fin(infile);
ofstream fout(outfile);

int wordLength, wordIndex;

char word[DIM];

int firstSeqApparitionCount[MAXINDEX], secondSeqApparitionCount[MAXINDEX];

string wordCode;

struct Solution {

	vector<char> firstWord;
	vector<char> secondWord;

} solution;

int compareWords(vector<char> firstWord, vector<char> secondWord) {

	if (firstWord.size() > secondWord.size()) {

		secondWord.resize(firstWord.size());

	}
	else {

		firstWord.resize(secondWord.size());

	}

	for (int index = 0; index < firstWord.size(); ++index) {

		if (firstWord[index] > secondWord[index]) {

			return 1;

		}
		else if (secondWord[index] > firstWord[index]) {

			return -1;

		}

	}

	return 0;

}

void tryLengths(int firstWordLength, int secondWordLength) {

	int firstWordStartIndex, secondWordStartIndex = wordLength - secondWordLength + 1;

	if (wordIndex % 2 == 0) {

		firstWordStartIndex = secondWordLength + 1;

	}
	else {

		firstWordStartIndex = 1;

	}

	for (int positionInCode = 0, index = 1; positionInCode < wordCode.size(); ++positionInCode) {

		char currChar = wordCode[positionInCode];

		if (currChar == 'A') {

			for (int tempIndex = index; tempIndex <= index + firstWordLength - 1; ++tempIndex) {

				if (word[tempIndex] != word[firstWordStartIndex + tempIndex - index]) {

					return;

				}

			}

			index += firstWordLength;

		}
		else {

			for (int tempIndex = index; tempIndex <= index + secondWordLength - 1; ++tempIndex) {

				if (word[tempIndex] != word[secondWordStartIndex + tempIndex - index]) {

					return;

				}

			}

			index += secondWordLength;

		}

	}

	vector<char> firstWord, secondWord;
	
	for (int index = firstWordStartIndex; index <= firstWordStartIndex + firstWordLength - 1; ++index) {

		firstWord.push_back(word[index]);
	}

	for (int index = secondWordStartIndex; index <= secondWordStartIndex + secondWordLength - 1; ++index) {

		secondWord.push_back(word[index]);

	}

	if (solution.firstWord.empty() || compareWords(firstWord, solution.firstWord) < 0) {

		solution.firstWord = firstWord;
		solution.secondWord = secondWord;

	}

}

int main() {

	fin >> wordIndex >> wordLength;

	fin >> word + 1;

	firstSeqApparitionCount[1] = secondSeqApparitionCount[2] = 1;

	string firstWordCode = "A", secondWordCode = "B";

	for (int index = 3; index <= wordIndex; ++index) {

		firstSeqApparitionCount[index] = firstSeqApparitionCount[index - 2] + firstSeqApparitionCount[index - 1];
		secondSeqApparitionCount[index] = secondSeqApparitionCount[index - 2] + secondSeqApparitionCount[index - 1];

		wordCode = firstWordCode + secondWordCode;

		firstWordCode = secondWordCode;
		secondWordCode = wordCode;

	}

	for (int firstWordLength = 1; firstSeqApparitionCount[wordIndex] * firstWordLength < wordLength; ++firstWordLength) {

		int secondWordLength = wordLength - firstSeqApparitionCount[wordIndex] * firstWordLength;

		if (secondWordLength % secondSeqApparitionCount[wordIndex] != 0)
			continue;

		secondWordLength /= secondSeqApparitionCount[wordIndex];

		tryLengths(firstWordLength, secondWordLength);

	}

	if (solution.firstWord.empty()) {

		fout << ERROR_MESSAGE;

	}
	else {

		for (vector<char>::iterator it = solution.firstWord.begin(); it != solution.firstWord.end(); ++it)
			fout << *it;

		fout << "\n";

		for (vector<char>::iterator it = solution.secondWord.begin(); it != solution.secondWord.end(); ++it)
			fout << *it;

	}

	return 0;

}

//Trust me, I'm the Doctor!
//Miriam e tare!