You are surfing the internet. You are currently on the home page of a website. There is a browser history that acts as a stack to keep track of the sites you visit. Currently, the history shows $"/$ home". You can perform the following operations:

$$ You can go back to the previous page. If the history is like "home$/$food$/$menu$"$ and you are currently in "food" page. Then you will be directed to the "home" page.

You can go forward. If the history is like "home$/$food$/$menu and you are currently in "food" page. Then you will be directed to the "menu" page.

$$ You can visit a page by clicking a link. This will delete all the forward pages from that point in history and add a new page in history. If the history is like "home$/$food$/$menu and you are currently in "food" page. You will visit the "diet" page. Then the history will be "home$/$food$/$diet

After a series of operations, find the history contents

Notes

Clicking back from the home page will not do anything Clicking forward from the last page will not do anything

If the input is "back", you will go back in history if it is forward go forward else go to given page