import java.util.*;
import java.lang.*;
 
class Main
{
    public static String comboFrom(String possibleChars, int charsToTake) {
        //randomly shuffle the chars using Collections.shuffle
        List<Character> chars = new ArrayList<Character>(possibleChars.length());
        for (char c : possibleChars.toCharArray()) {
            chars.add(new Character(c));
        }
        Collections.shuffle(chars);
        String result = ""; 
        //Take the first 'charsToTake' characters - these will be totally random
        //thanks to the shuffle
        int taken=0;
        for (Character c : chars) {
            result += c.charValue();
            if (taken >= charsToTake) break;
            taken += 1;
        }
        return result;
    }
    public static void main (String[] args) throws java.lang.Exception
    {
        for (int i=0; i < 30; i++) {
            System.out.println(comboFrom("abcdefghijkl@#%", 5));
        }
    }
}

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