def isBalanced(s):
    closeToOpen = { ")" : "(", "]" : "[", "}" : "{" }
    Stack = []

    for x in s:
        if x in closeToOpen:
            if Stack and Stack[-1] == closeToOpen[x]:
                Stack.pop()
            else:
                return "NO"
        else:
            Stack.append(x)

    return "NO" if len(Stack) > 0 else "YES"