I need help making this program work and run.

public class Main { public static void main(String[] args) { String input = "aaaaa"; String encoded = RunLengthEncoder.encode(input); System.out.println("Encoded string: " + encoded); } }

public class RunLengthEncoder { public static String encode(String s) { StringBuilder result = new StringBuilder(); int i = 0; while (i < s.length()) { int j = i; while (j < s.length() && s.charAt(j) == s.charAt(i)) { j++; } int count = j - i; if (count > 4) { result.append("/"); if (count < 10) { result.append("0"); } result.append(count); result.append(s.charAt(i)); } else { for (int k = 0; k < count; k++) { result.append(s.charAt(i)); } } i = j; } return result.toString(); }

}