public static String increasingSubstrings(String s) {
		List<String> list=new ArrayList<>();
		for (int i=0,ni,n=s.length();i<n;i=ni) {
			int len=1;
			for (ni=i+1;ni<s.length();++ni) {
				if (Character.toLowerCase(s.charAt(ni))==Character.toLowerCase(s.charAt(ni-1))+1)++len;
				else break;
			}
			if (len>=3) list.add(s.substring(i,ni));
		}
		StringBuilder rel=new StringBuilder();
		for (String str:list) rel.append(str).append(";");
		return rel.length()==0?"":rel.substring(0,rel.length()-1);
	}