check = {")":"(" , "]":"[" , "}":"{" }
    stack = []
    for c in s:
        if c in check.values():
            stack.append(c)
        elif stack and check[c] == stack[-1]:
            stack.pop()
        else:
            return 'NO'
    if stack == []:
        return 'YES'
    else:
        return 'NO'