Background

6.373

The world is independent of my will.

6.374

Even if everything we hope for happens,

in the end it can only be called a gift of fate.

If you ask why, it is because between will and the world,

the logical connection that can guarantee this does not exist.

Ludwig Josef Johann Wittgenstein [Tractatus Logico-Philosophicus]

How long has it been since my twin brother passed away…

Since then, I have kept that stuffed doll.

After that, I was only a shadow… and this stuffed doll was the real me…

That is not so bad either.

I think it is enough if the current me disappears…

But those two people saved someone like me.

One of them was Yuki-nee…

She came back to my side again…

Bringing Minamori-nii… back to our side…

Mizukami Yuki-nee, a gentle older sister.

Someone who once liked Minamori-nii very much……

On the way back…

A slope we usually would not pass…

While climbing that slope…

I saw the sun at night.

A huge sunflower that was nearby, yet I never noticed it.

The night dew made its fuzz glow white.

The deep blue moonlight and the yellow sunflower…

It was as if the positions of the sun and the moon were reversed…

The sun, originally so dazzling, was on the ground, and the moon, which could only shine behind it, was in the sky…

The yellow sunflower was dyed deep blue.

That sight was very beautiful…

But the sunflower, blooming with all its might, instead looked like something fragile.

The sunflower stretching toward the sky at night…

Inside the car, I kept chasing its silhouette…

The sun illuminated by the moonlight at night.

The sun dyed deep blue…

Its figure… I kept chasing it……

On the rooftop lit by moonlight…

A shadow…

Clearly just a shadow… yet it seemed… to be confronting something…

Minamori-nii…

A statue under the moon, a shadow.

His chest flickered in the wind.

In the hand placed before his chest was… that small knife from back then.

The same posture as seven years ago.

The only difference was that there was only one shadow there.

That knife seemed to have been stabbed into his body by himself.

It is a curse…

This is only natural…

It is not some mental illness…

It is a curse…

A curse placed on us survivors…

Perhaps, not only Takushi-nii… but even Yuki-nee is cursing us…

So it ended up like this…

My brother stabbed his own chest…

Destroyed my other half…

And then… he will send many people back to the sky…

The day of returning to the sky.

The day of giving back the soul.

What Takushi-nii did to me that day.

That act… of killing Yuki-nee…

He wants to do it once again…

This time… together with many people…

No…

That is… me…

It is that… slope…

That slope where two people saw the sunflower together…

…I said I wanted to climb that slope… to look for Dad’s soul…

I thought that if I reached beyond that slope, I could take back Dad’s soul… and Dad would come back to life…

If I crossed the sunflower road… and went toward that big slope that extends into the sky the sunflower faces… Then, probably, Dad’s soul would be there…

The big slope… of Dad’s hometown…

My brother’s body floated in the air…

I jumped out without a word.

Ah… so that is how it is…

Yuki-nee felt like this too…

There is no reason to it…

Just because the person I like jumped toward the sky…

I wanted to grab that body…

I—

Problem Description

You are playing a galgame when the power suddenly goes out. You run to the property management office to ask, and find out it was because a bald guy kicked the transformer, and it may take a long time to fix. So you decide to think about a data structure problem you saw before:

Define the weight of a sequence as the number of distinct numbers in it. For example, $[1,2,3,3]$ has weight $3$.

Now there are $n$ sequences. For each sequence, we choose a non-empty contiguous substring, and concatenate them. Compute the sum of the weights of the resulting sequence over all choices.

If a sequence can be obtained in multiple ways, count it multiple times.

This problem includes modification operations; see the input format.

Since the result may be too large, output the answer $\bmod 19260817$.

Input Format

The first line contains two integers $n,m$, meaning there are $n$ sequences and $m$ modifications.

The second line contains $n$ integers; the $i$-th number is $len_i$, meaning the length of the $i$-th sequence.

Then follow $n$ lines; the $i$-th line contains $len_i$ integers, representing the $i$-th sequence.

Then follow $m$ lines; each line contains three integers $x,y,z$, meaning change the $y$-th element of the $x$-th sequence to $z$.

Output Format

Output $m + 1$ lines, each containing one integer, representing the answer for the initial state and after each modification, in order.

2 5
6 6
1 3 1 1 3 2 
2 3 3 2 1 1 
1 1 1
1 1 2
1 1 2
1 1 1
1 1 1

1158
1158
1168
1168
1158
1158

Hint

Idea: nzhtl1477, Solution: nzhtl1477, Code: nzhtl1477, Data: nzhtl1477 ( partially uploaded )

$1 \leq n,m,len_i \leq 10^5$. The elements in the sequences are all $32$-bit integers, and $\sum len_i \leq 10^5$.

There are $50$ test cases.

Translated by ChatGPT 5