accum

package com.company;
import java.lang.*;
import java.util.Locale;

class Accumul {

    public static String accum(String s) {
        // your code
        var strb = new StringBuilder("");
        for (int i = 0; i < s.length(); i++) {
            String toBeAdded = String.valueOf(s.charAt(i));
            strb.append(toBeAdded.toUpperCase(Locale.ROOT));
            for (int aux = i; aux > 0; aux--) {
                strb.append(toBeAdded);
            }
            strb.append("-");
        }
        strb.setLength(Math.max(strb.length() - 1, 0));
        return strb.toString();
    }
}

public class Main {

    public static void main(String[] args) {
        System.out.println(Accumul.accum("abcd"));
    }
}