class MinStack {
public:
    /** initialize your data structure here. */
    MinStack() {
        
    }
    
    void push(int x) {
        myStack.push(x);
        update(x);
    }
    
    void pop() {
        if(myStack.top()==helpStack.top())
            helpStack.pop();
        myStack.pop();
    }
    
    int top() {
        return myStack.top();
    }
    
    int getMin() {
        return helpStack.top();
    }
    
    void update(int x){
        if(helpStack.empty()||x<=helpStack.top())
            helpStack.push(x);
    }
    
    stack<int> myStack;
    stack<int> helpStack;
};

/**
 * Your MinStack object will be instantiated and called as such:
 * MinStack obj = new MinStack();
 * obj.push(x);
 * obj.pop();
 * int param_3 = obj.top();
 * int param_4 = obj.getMin();
 */