public class Main {
    public static void main(String[] args) {
        char[] str = {'d','a','b','c','d'};
        for(char a:str){
            System.out.print(a);
        }
        System.out.println("");
        int[] number = new int[26];
        for(char a:str){
            number[a-'a']++ ;
        }
        for(int i=0;i<str.length;i++){
            if(number[str[i]-'a']>1){
                number[str[i]-'a']-- ;
                str[i]='0';
            }
        }
        for(char a:str){
            if(a!='0')
            System.out.print(a);
        }
    }
}