class MinStack {
Stack stack = new Stack();
Stack minStack = new Stack();
public void push(int x) {
if(stack.isEmpty()){
minStack.push(x);
} else{
minStack.push(Math.min(x,minStack.peek()));
}
stack.push(x);
}
public void pop() {
if(stack.isEmpty()) return;
else {
stack.pop();
minStack.pop();
}
}
public int top() {
return stack.peek();
}
public int getMin() {
return minStack.peek();
}
}