class Stack{
private:
    struct Node{
        int data;
        Node* next;
    };
    Node* top;
    int count;
public:
    Stack():count(0),top(nullptr){}

    void push(int data){
        Node* node=new Node();
        node->data=data;
        node->next=top;
        top=node;
        count++;
    }

    void pop(){
        if(isEmpty())return;
        Node* node=top;
        top=node->next;
        delete node;
        count--;
    }

    int mTop(){
        return top->data;
    }

    bool isEmpty(){
        return count==0;
    }
};
int main(){
    Stack* st=new Stack();
    st->push(1);
    st->push(2);
    st->push(3);
}

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