public int readKnots(String knots) {
		int length = knots.length();
		StringBuffer sBuffer = new StringBuffer();
		for(int i = 1;i < length;i++){
			int now = 0;
			while(knots.charAt(i) == 'X'){
				now++;
				i++;
			}
			sBuffer.append(now);
		}
		return Integer.parseInt(sBuffer.toString());
	}