/* package whatever; // don't place package name! */

import java.util.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
 	public static void main(String[] args){
		String s = "abcd";
		printPermutations(s, "");
	}

	private static void printPermutations(String s, String t){
		if(s == null || s.length() == 0){
			System.out.println(t);
			return;
		}

		for(int k=0; k<s.length(); k++){
			String target = t + s.charAt(k);
			printPermutations(s.substring(0,k)+s.substring(k+1), target);
		}
	}
}