/**
knakul853
**/

class Solution {
public:
    bool isValid(string s) {

        stack<char>st;

        int n = (int)s.size();

        for(int i=0;i<n;i++)
        {
            if(s[i] =='{' || s[i] == '(' || s[i] =='[')
            {
                st.push(s[i]);
                continue;
            }

            if(st.size() <= 0) return 0;

            else{

                char open = st.top();
                char close = s[i];

                if(open  == '{' && close !='}'
                   or open =='[' && close !=']'
                   or open == '(' && close != ')'
                  )
                    return false;

                st.pop();
            }
        }

        return st.empty();

    }
};