stack<char> Brackets;
for(char c : s)
{
    if(c == '(' || c == '[' || c == '{')
        Brackets.push(c);
    else 
    {

        if(Brackets.empty()) return "NO";
        char top = Brackets.top();
        if((c == ')' && top != '(')
        || (c == ']' && top != '[')
        || (c == '}' && top != '{'))
            return "NO";
        else 
            Brackets.pop();   
    }
}
        return Brackets.empty() ? "YES" : "NO";

}