Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: 1
at java.lang.String.charAt(String.java:455)
at java.util.regex.Matcher.appendReplacement(Matcher.java:532)
at java.util.regex.Matcher.replaceAll(Matcher.java:636)
at java.lang.String.replaceAll(String.java:1706)
at a.main(a.java:6)