Qi also holds a photograph of himself standing on the footbridge over the Yarra River on Melbourne's south bank, with the Crown Casino, the largest casino in the southern hemisphere, on the left side of the bridge.

Qi Yi came to the casino in Melbourne, and what he wanted to do had nothing to do with gambling at all.

Qi Yi is also looking for someone, looking for the person who took the photo he is holding in his hand at the moment.

In a place like Melbourne's Southbank, where there are many high-rise buildings, it is not easy to find out who took the photo and which floor of which building when the photo was taken.

At this moment, although Qi Yi is taking a photo to study, what he really has to face is not an iconological problem, but a statistical, to be precise, mathematical problem.

This kind of search will involve a huge amount of computation, and in addition to some specific conditions, it will also need some specific conditions to find it successfully.

The photo in his hand was not taken by Qi Yi himself, so he had no way to set the conditions in advance.

Qi also wants to use the knowledge he has learned in the past four years in the world's top mathematics schools and institutions to find someone who has not seen him for four years, has not spoken for five years, and has long since completely disappeared from his life.

Mathematics lingers around everyone, as long as people who have studied books, they have studied mathematics, but people who really like mathematics, out of ten, may not be able to find one.

And there are even fewer people who can apply mathematical methods to life.

In other words, the average person is not interested in applied mathematics, and the general public wants mathematics to be as far away from them as possible.

But Qi Yi is not an ordinary person.

One year after Qi Yi was admitted to the Department of Probability and Statistics of the School of Mathematics of Peking University, the professor of the Summer School of Applied Mathematics resigned from his original graduate teaching assistant and replaced Qi Yi as a teaching assistant.

In the words of the professor, Qi was born for applied mathematics.

Perhaps there are many unusual people in Peking University, so the School of Mathematics of Peking University opens the Summer School of Applied Mathematics every summer, which is not only deserted, but also quite popular.

However, it has never been done before for a student like Qi Yi, who has just finished his freshman year, to be a teaching assistant.

Also because of the professor's strong recommendation, Qi Yi just got an exchange place at Stanford University in the United States as soon as he was a sophomore.

Qi Yi, who is looking for someone, needs to face the trickier problem at the moment is that Melbourne is a completely unfamiliar city to him, and the only thing he can use to find people is the only photo he has in his hand at this moment.

In this way, the equation full of unknowns that Qi Yi uses to find people has extremely limited data and conditions that can be used to solve the problem.

It's a bit of a coincidence that the "husband" is difficult to cook without rice.

Mathematics is Qi Yi's strength, no matter how large the amount of calculations, he is not afraid, only the possibility of no solution to the equation is what Qi Yi is most worried about.

Once this multivariate equation is unsolved, Qi Yi will have no way to find the person he is looking for.

Let Qi Yi come to Melbourne to find someone, it is a text written three years ago.

This text made Qi Yi understand the reason why Yan Yun suddenly broke up with him five years ago, when he was about to be in his third year of high school.

This text was supposed to be a "letter" sent to him, but the person who wrote it did not choose to send it, but wrote it as a blog post that was not made public.

…………………………

Qi Yi and Yan Yun met in the first year of high school, fell in love in the second year of high school, and did not say a word in the entire third year of high school.

I started falling in love in my second year of high school, should it be considered early love?

Qi is also the school grass that is indispensable, and Yan Yun is ......

Yan Yun is nothing, she is the inconspicuous one in the crowd.

The four words "inconspicuous" are already the highest evaluation for Yan Yun.

Before he was inconspicuous, Yan Yun had a serious black physique and had a very poor popularity.

Yan Yun's recruitment is precisely targeted physique, because of various strange reasons, Yan Yun has been targeted from childhood to adulthood.

…………………………

Qi Yi was able to see the words Yan Yun wrote three years ago, and the chance came from an email he received two weeks ago.

The sender has nothing to do with Qi, strictly speaking, the sender is not a person at all, but a machine.

This email is from the MSN space team at Microsoft.

The content of the email has nothing to do with Qi.

It is said that the MSN space service will be completely shut down in March of this year, and from this time of receiving the email, users will no longer be able to post new logs in the MSN space.

The main purpose of Microsoft sending this email to users is to allow users to give their own space to "move".

This is the fourth time Qi Yi has received an email about this matter.

Microsoft is recommending that users of MSN Space move to Automattic's WordPress blogging platform.

But WordPress awareness in China is too low, and a fourth email received two weeks ago provided the message that users in China could move MSN Space to Sina Blog.

Sina's ability to stand out in the subsequent Weibo era is also due to the "moving project" in cooperation with Microsoft to some extent.

At this time, Qi Yi didn't have any special feelings about this email, except for the fourth time wondering why Microsoft sent him a moving email.

Qi Yiyi has never used MSN, and second, he has never written blog logs anywhere.

The fact that MSN Space is going to stop serving and need to move is completely unrelated to Qi Yi, and the whole thing is irrelevant.

Qi Yi interned at Microsoft Research Asia in his junior year, and he knew very well that Microsoft was not a company that would spam and harass users who had nothing to do with its products.

Forget it again and again, and Qi Yi, who received the "ultimatum" for the fourth time, began to wonder if he had really registered for MSN space at some time and inadvertently.

Qi Yi's Hotmail mailbox was registered by Yan Yun for him when he hadn't broken up in his sophomore year of high school, this is his only mailbox, and it is also the only thing that still has some relationship between him and Yan Yun.

Five years ago, Yan Yun asked to break up, and returned all the "warm" letters that Qi Yi had written to her on stationery the year before, and she also asked Qi Yi to return all the letters she wrote to Qi Yi.

All the "real things" related to the relationship between the two have all been returned to their places at Yan Yun's request.

It's just that Yan Yun used the combination of the pinyin of Qi Yi's name and the number of his birthday to help register the mailbox, which has no special meaning at all.

Qi Yi later got used to this mailbox and never changed it again.

When Yan Yun gave Qi Yi the account password, she said that when she registered one herself in a few days, she could communicate with Qi Yi by email, otherwise it would be quite tiring to write on the letterhead.

But a few days later, when Qi Yi was just about to celebrate the "first anniversary of love" with Yan Yun, Yan Yun suddenly broke up with him inexplicably and without looking back.

Yan Yun's decision when he proposed to break up at that time made Qi Yi feel painful.

But after all, it was five years ago to break up, and Qi Yi at this moment can already think of that time relatively calmly.

Qi Yi looked at his mailbox, why did he keep receiving messages from MSN Space asking him to move?

Qi Yi thought about it and tried to log in to MSN with his own email address.

Then, Qi Yi found that he really had a registration MSN space, and there was a blog post written five years ago in the space, and the first and last post in his space, saying that it was a blog post was actually only one sentence:

Haha~ I helped my grandfather register the space today~

At the bottom of this blog post is a comment written five years ago:

"Oh lala, who signed up? It's really amazing~"

The nickname of the person who wrote the review was "crooked in the crooked".

Five years ago, Qi Yi, at the age of eighteen, only Yan Yun would call him grandpa in an astonishing voice.

Qi Yi clicked on the space of the commenter, and the content of this space is also scattered, but it is much richer than Qi Yi's.

There are two short and one long in it, and three blog posts.

The first article is very short, and the time of release is the same as the one five years ago in Qi Yispace. The content is also only a short sentence:

"I knew you would click in and see, oh lala, such a powerful person, of course it's me~"

The second part is relatively long, having been published three years ago.

The third article has just been released less than a month ago, and there are not a few lines written:

"Just moved my family to Southbank today.

I received an email from MSN Space asking me to "move".

It turns out that "moving" is not just a matter of real life.

However, the space that has been open for five years and has never been visited by anyone seems to need me to move something.

Let's not move.

On the last day when I can still update the space, I picked up my camera and said goodbye to my MSN space with a view of the view outside the window at the moment.

Memories have always been there, and they can't be moved or removed. ”