private static void tryDo(String s, int i, int j){
		int len = j-i;
		int sLen = s.length();
		for(int k=0;k<len;k++){
			if((j+k<allowed && j+k>=sLen) || (i+k<sLen && j+k<sLen && s.charAt(i+k)==s.charAt(j+k))){
				continue;
			} else {
				return;
			}
		}
		max = Math.max(len*2, max);
	}