import java.util.*;
import java.util.Stack;
public class Solution {
Stack<Integer> numbers = new Stack<>();
Stack<Integer> minStack = new Stack<>();
public void push(int node) {
if (numbers.isEmpty()) {
numbers.push(node);
minStack.push(node);
} else {
numbers.push(node);
if (node < minStack.peek()) {
minStack.push(node);
} else {
minStack.push(minStack.peek());
}
}
}
public void pop() {
numbers.pop();
minStack.pop();
}
public int top() {
return numbers.peek();
}
public int min() {
return minStack.peek();
}
}