vector<int> getMax(vector<string> operations) {
    stack<int> s;
    stack<int> maxStack;    
    vector<int> results;
    for(auto item : operations){
        string op;
        string val;
        stringstream ss(item);
        ss >> op >> val;
        switch (stoi(op)) {
            case 1:
                s.push(stoi(val));
                if(!maxStack.empty() && maxStack.top()<=stoi(val))
                    maxStack.push(stoi(val));
                if(maxStack.empty())
                    maxStack.push(stoi(val));
                break;
            case 2: 
                if(!maxStack.empty() && !s.empty() && maxStack.top() == s.top())
                    maxStack.pop();
                if(!s.empty())
                    s.pop();
                break;
            case 3: 
                if(!maxStack.empty())
                    results.push_back(maxStack.top());
                else results.push_back(0);
                break;
        }
    }
    return results;
}