brackets = {
    "}": "{",
    ")": "(",
    "]": "["
}

def isBalanced(s):
    # Write your code here
    stack = []
    for x in s:
        if x in brackets.values():
            stack.append(x)
        elif stack and brackets[x] == stack[-1]:
            stack.pop()
        else:
            return "NO"
    if not stack:
        return "YES"
    return "NO"