Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.

The brackets must close in the correct order, "()" and "()[]{}" are all valid but "(]" and "([)]" are not.

class Solution {    public boolean isValid(String s) {        Stack
    
      tag = new Stack<>();				try {			for (char c : s.toCharArray()) {				switch (c) {				case '(':					tag.push(')');					break;				case ')':					if (c != tag.pop()) return false;					break;				case '[':					tag.push(']');					break;				case ']':					if (c != tag.pop()) return false;					break;				case '{':					tag.push('}');					break;				case '}':					if (c != tag.pop()) return false;					break;				default:					break;				}			}		} catch (Exception e) {			return false;		}				return tag.empty();    }}