import java.util.Scanner;

/**
 *
 * Ashish Patel
 * e: ashishsushilPatel@gmail.com
 * w: https://ashish.me
 *
 */

class SubsequenceOfString {

  static boolean isSubSeq(String s1, String s2, int n, int m){
    int j = 0;
    for(int i = 0; i < n && j < m; i++){
      System.out.println(s1.charAt(i) + " " +  s2.charAt(j));
      if(s1.charAt(i) == s2.charAt(j)){
        j++;
      }
    }
    return j == m;
  }

  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
		int n, m;
		n = sc.nextInt();
		m = sc.nextInt();

		String s1, s2;
		s1 = sc.next();
		s2 = sc.next();

		System.out.println(isSubSeq(s1, s2, n, m));
  }
}