public int titleToNumber(String s) {
		int n = s.length();
		int count = 0;
		if (n == 0)
			return count;
		for (int i = 0; i < n; i++) {
			count += (s.charAt(i) - 64) * Math.pow(26, n - 1 - i);
		}
		return count;
	}