class Solution {

public static List<String> generatePossibleNextMoves(String s) {

List<String> ans = new ArrayList<>();

if (s.length() < 2) {

return ans;

}

if (s.equals("--")) {

return ans;

}

int i = 0;

while (i < s.length()-1) {

if (s.charAt(i) == s.charAt(i+1) && s.charAt(i) == '+') {

StringBuilder sb = new StringBuilder();

sb.append(s.substring(0, i));

sb.append('-');

sb.append('-');

sb.append(s.substring(i+2));

ans.add(sb.toString());

}

i++;

}

return ans;

}

}