1 import java.util.Stack;
 2  
 3 public class Solution {
 4  
 5     Stack<Integer> dataStack =new Stack<Integer>();
 6     Stack<Integer> minStack =new Stack<Integer>();
 7     public void push(int node) {
 8         dataStack.push(node);
 9         if(minStack.empty()||minStack.peek()>node){
10             minStack.push(node);
11         }else{
12             minStack.push(minStack.peek());
13         }
14     }
15      
16     public void pop() {
17         dataStack.pop();
18        minStack.pop();
19     }
20      
21     public int top() {
22         return dataStack.peek();
23     }
24      
25     public int min() {
26         return minStack.peek();
27     }
28 }