apaz/codeforces-genesys huggingface dataset:
You are an expert competitive programmer. You will be given a problem statement, test case constraints and example test inputs and outputs. Please reason step by step about the solution (that must respect memory and time limits), then provide a complete implementation in python3.

Your solution must read input from standard input (cin), write output to standard output (cout).
Do not include any debug prints or additional output.

Put your final solution within a single code block:
```python
<your code here>
```

Execution time limit: 2.0 seconds
Memory limit: 256.0 MB

# Problem
Olga came to visit the twins Anna and Maria and saw that they have many cookies. The cookies are distributed into bags. As there are many cookies, Olga decided that it's no big deal if she steals a bag. However, she doesn't want the sisters to quarrel because of nothing when they divide the cookies. That's why Olga wants to steal a bag with cookies so that the number of cookies in the remaining bags was even, that is, so that Anna and Maria could evenly divide it into two (even 0 remaining cookies will do, just as any other even number). How many ways there are to steal exactly one cookie bag so that the total number of cookies in the remaining bags was even?

## Input Format
The first line contains the only integer n (1 ≤ n ≤ 100) — the number of cookie bags Anna and Maria have. The second line contains n integers ai (1 ≤ ai ≤ 100) — the number of cookies in the i-th bag.

## Output Format
Print in the only line the only number — the sought number of ways. If there are no such ways print 0.

## Examples
```input
1
1
```
```output
1
```
-----
```input
10
1 2 2 3 4 4 4 2 2 2
```
```output
8
```
-----
```input
11
2 2 2 2 2 2 2 2 2 2 99
```
```output
1
```

## Note
In the first sample Olga should take the only bag so that the twins ended up with the even number of cookies.

In the second sample Olga can take any of five bags with two cookies or any of three bags with four cookies — 5 + 3 = 8 ways in total.

In the third sample, no matter which bag with two cookies Olga chooses, the twins are left with 2 * 9 + 99 = 117 cookies. Thus, Olga has only one option: to take the bag with 99 cookies.

Now solve the problem and return the code.
You are an expert competitive programmer. You will be given a problem statement, test case constraints and example test inputs and outputs. Please reason step by step about the solution (that must respect memory and time limits), then provide a complete implementation in python3.

Your solution must read input from standard input (cin), write output to standard output (cout).
Do not include any debug prints or additional output.

Put your final solution within a single code block:
```python
<your code here>
```

Execution time limit: 2.0 seconds
Memory limit: 256.0 MB

# Problem
Anna and Maria are in charge of the math club for junior students. When the club gathers together, the students behave badly. They've brought lots of shoe laces to the club and got tied with each other. Specifically, each string ties together two students. Besides, if two students are tied, then the lace connects the first student with the second one as well as the second student with the first one.

To restore order, Anna and Maria do the following. First, for each student Anna finds out what other students he is tied to. If a student is tied to exactly one other student, Anna reprimands him. Then Maria gathers in a single group all the students who have been just reprimanded. She kicks them out from the club. This group of students immediately leaves the club. These students takes with them the laces that used to tie them. Then again for every student Anna finds out how many other students he is tied to and so on. And they do so until Anna can reprimand at least one student.

Determine how many groups of students will be kicked out of the club.

## Input Format
The first line contains two integers n and m — the initial number of students and laces ($$1 \leq n \leq 100, 0 \leq m \leq \frac{n(n-1)}{2}$$). The students are numbered from 1 to n, and the laces are numbered from 1 to m. Next m lines each contain two integers a and b — the numbers of students tied by the i-th lace (1 ≤ a, b ≤ n, a ≠ b). It is guaranteed that no two students are tied with more than one lace. No lace ties a student to himself.

## Output Format
Print the single number — the number of groups of students that will be kicked out from the club.

## Examples
```input
3 3
1 2
2 3
3 1
```
```output
0
```
-----
```input
6 3
1 2
2 3
3 4
```
```output
2
```
-----
```input
6 5
1 4
2 4
3 4
5 4
6 4
```
```output
1
```

## Note
In the first sample Anna and Maria won't kick out any group of students — in the initial position every student is tied to two other students and Anna won't be able to reprimand anyone.

In the second sample four students are tied in a chain and two more are running by themselves. First Anna and Maria kick out the two students from both ends of the chain (1 and 4), then — two other students from the chain (2 and 3). At that the students who are running by themselves will stay in the club.

In the third sample Anna and Maria will momentarily kick out all students except for the fourth one and the process stops at that point. The correct answer is one.

Now solve the problem and return the code.
You are an expert competitive programmer. You will be given a problem statement, test case constraints and example test inputs and outputs. Please reason step by step about the solution (that must respect memory and time limits), then provide a complete implementation in python3.

Your solution must read input from standard input (cin), write output to standard output (cout).
Do not include any debug prints or additional output.

Put your final solution within a single code block:
```python
<your code here>
```

Execution time limit: 0.5 seconds
Memory limit: 256.0 MB

# Problem
wHAT DO WE NEED cAPS LOCK FOR?

Caps lock is a computer keyboard key. Pressing it sets an input mode in which typed letters are capital by default. If it is pressed by accident, it leads to accidents like the one we had in the first passage.

Let's consider that a word has been typed with the Caps lock key accidentally switched on, if:

- either it only contains uppercase letters;
- or all letters except for the first one are uppercase.

In this case we should automatically change the case of all letters. For example, the case of the letters that form words "hELLO", "HTTP", "z" should be changed.

Write a program that applies the rule mentioned above. If the rule cannot be applied, the program should leave the word unchanged.

## Input Format
The first line of the input data contains a word consisting of uppercase and lowercase Latin letters. The word's length is from 1 to 100 characters, inclusive.

## Output Format
Print the result of the given word's processing.

## Examples
```input
cAPS
```
```output
Caps
```
-----
```input
Lock
```
```output
Lock
```

Now solve the problem and return the code.
You are an expert competitive programmer. You will be given a problem statement, test case constraints and example test inputs and outputs. Please reason step by step about the solution (that must respect memory and time limits), then provide a complete implementation in python3.

Your solution must read input from standard input (cin), write output to standard output (cout).
Do not include any debug prints or additional output.

Put your final solution within a single code block:
```python
<your code here>
```

Execution time limit: 2.0 seconds
Memory limit: 256.0 MB

# Problem
Everybody knows that opposites attract. That is the key principle of the "Perfect Matching" dating agency. The "Perfect Matching" matchmakers have classified each registered customer by his interests and assigned to the i-th client number ti ( - 10 ≤ ti ≤ 10). Of course, one number can be assigned to any number of customers.

"Perfect Matching" wants to advertise its services and publish the number of opposite couples, that is, the couples who have opposite values of t. Each couple consists of exactly two clients. The customer can be included in a couple an arbitrary number of times. Help the agency and write the program that will find the sought number by the given sequence t1, t2, ..., tn. For example, if t = (1,  - 1, 1,  - 1), then any two elements ti and tj form a couple if i and j have different parity. Consequently, in this case the sought number equals 4.

Of course, a client can't form a couple with him/herself.

## Input Format
The first line of the input data contains an integer n (1 ≤ n ≤ 105) which represents the number of registered clients of the "Couple Matching". The second line contains a sequence of integers t1, t2, ..., tn ( - 10 ≤ ti ≤ 10), ti — is the parameter of the i-th customer that has been assigned to the customer by the result of the analysis of his interests.

## Output Format
Print the number of couples of customs with opposite t. The opposite number for x is number  - x (0 is opposite to itself). Couples that only differ in the clients' order are considered the same.

Note that the answer to the problem can be large enough, so you must use the 64-bit integer type for calculations. Please, do not use the %lld specificator to read or write 64-bit integers in С++. It is preferred to use cin, cout streams or the %I64d specificator.

## Examples
```input
5
-3 3 0 0 3
```
```output
3
```
-----
```input
3
0 0 0
```
```output
3
```

## Note
In the first sample the couples of opposite clients are: (1,2), (1,5) и (3,4).

In the second sample any couple of clients is opposite.

Now solve the problem and return the code.
You are an expert competitive programmer. You will be given a problem statement, test case constraints and example test inputs and outputs. Please reason step by step about the solution (that must respect memory and time limits), then provide a complete implementation in python3.

Your solution must read input from standard input (cin), write output to standard output (cout).
Do not include any debug prints or additional output.

Put your final solution within a single code block:
```python
<your code here>
```

Execution time limit: 2.0 seconds
Memory limit: 256.0 MB

# Problem
There are n boys and m girls attending a theatre club. To set a play "The Big Bang Theory", they need to choose a group containing exactly t actors containing no less than 4 boys and no less than one girl. How many ways are there to choose a group? Of course, the variants that only differ in the composition of the troupe are considered different.

Perform all calculations in the 64-bit type: long long for С/С++, int64 for Delphi and long for Java.

## Input Format
The only line of the input data contains three integers n, m, t (4 ≤ n ≤ 30, 1 ≤ m ≤ 30, 5 ≤ t ≤ n + m).

## Output Format
Find the required number of ways.

Please do not use the %lld specificator to read or write 64-bit integers in С++. It is preferred to use cin, cout streams or the %I64d specificator.

## Examples
```input
5 2 5
```
```output
10
```
-----
```input
4 3 5
```
```output
3
```

Now solve the problem and return the code.
You are an expert competitive programmer. You will be given a problem statement, test case constraints and example test inputs and outputs. Please reason step by step about the solution (that must respect memory and time limits), then provide a complete implementation in python3.

Your solution must read input from standard input (cin), write output to standard output (cout).
Do not include any debug prints or additional output.

Put your final solution within a single code block:
```python
<your code here>
```

Execution time limit: 2.0 seconds
Memory limit: 256.0 MB

# Problem
A subway scheme, classic for all Berland cities is represented by a set of n stations connected by n passages, each of which connects exactly two stations and does not pass through any others. Besides, in the classic scheme one can get from any station to any other one along the passages. The passages can be used to move in both directions. Between each pair of stations there is no more than one passage.

Berland mathematicians have recently proved a theorem that states that any classic scheme has a ringroad. There can be only one ringroad. In other words, in any classic scheme one can find the only scheme consisting of stations (where any two neighbouring ones are linked by a passage) and this cycle doesn't contain any station more than once.

This invention had a powerful social impact as now the stations could be compared according to their distance from the ringroad. For example, a citizen could say "I live in three passages from the ringroad" and another one could reply "you loser, I live in one passage from the ringroad". The Internet soon got filled with applications that promised to count the distance from the station to the ringroad (send a text message to a short number...).

The Berland government decided to put an end to these disturbances and start to control the situation. You are requested to write a program that can determine the remoteness from the ringroad for each station by the city subway scheme.

## Input Format
The first line contains an integer n (3 ≤ n ≤ 3000), n is the number of stations (and trains at the same time) in the subway scheme. Then n lines contain descriptions of the trains, one per line. Each line contains a pair of integers xi, yi (1 ≤ xi, yi ≤ n) and represents the presence of a passage from station xi to station yi. The stations are numbered from 1 to n in an arbitrary order. It is guaranteed that xi ≠ yi and that no pair of stations contain more than one passage. The passages can be used to travel both ways. It is guaranteed that the given description represents a classic subway scheme.

## Output Format
Print n numbers. Separate the numbers by spaces, the i-th one should be equal to the distance of the i-th station from the ringroad. For the ringroad stations print number 0.

## Examples
```input
4
1 3
4 3
4 2
1 2
```
```output
0 0 0 0
```
-----
```input
6
1 2
3 4
6 4
2 3
1 3
3 5
```
```output
0 0 0 1 1 2
```

Now solve the problem and return the code.
You are an expert competitive programmer. You will be given a problem statement, test case constraints and example test inputs and outputs. Please reason step by step about the solution (that must respect memory and time limits), then provide a complete implementation in python3.

Your solution must read input from standard input (cin), write output to standard output (cout).
Do not include any debug prints or additional output.

Put your final solution within a single code block:
```python
<your code here>
```

Execution time limit: 2.0 seconds
Memory limit: 256.0 MB

# Problem
A queen is the strongest chess piece. In modern chess the queen can move any number of squares in any horizontal, vertical or diagonal direction (considering that there're no other pieces on its way). The queen combines the options given to the rook and the bishop.

There are m queens on a square n × n chessboard. You know each queen's positions, the i-th queen is positioned in the square (ri, ci), where ri is the board row number (numbered from the top to the bottom from 1 to n), and ci is the board's column number (numbered from the left to the right from 1 to n). No two queens share the same position.

For each queen one can count w — the number of other queens that the given queen threatens (attacks). For a fixed attack direction only the first queen in this direction is under attack if there are many queens are on the ray of the attack. Obviously, for any queen w is between 0 and 8, inclusive.

Print the sequence t0, t1, ..., t8, where ti is the number of queens that threaten exactly i other queens, i.e. the number of queens that their w equals i.

## Input Format
The first line of the input contains a pair of integers n, m (1 ≤ n, m ≤ 105), where n is the size of the board and m is the number of queens on the board. Then m following lines contain positions of the queens, one per line. Each line contains a pair of integers ri, ci (1 ≤ ri, ci ≤ n) — the queen's position. No two queens stand on the same square.

## Output Format
Print the required sequence t0, t1, ..., t8, separating the numbers with spaces.

## Examples
```input
8 4
4 3
4 8
6 5
1 6
```
```output
0 3 0 1 0 0 0 0 0
```
-----
```input
10 3
1 1
1 2
1 3
```
```output
0 2 1 0 0 0 0 0 0
```

Now solve the problem and return the code.
You are an expert competitive programmer. You will be given a problem statement, test case constraints and example test inputs and outputs. Please reason step by step about the solution (that must respect memory and time limits), then provide a complete implementation in python3.

Your solution must read input from standard input (cin), write output to standard output (cout).
Do not include any debug prints or additional output.

Put your final solution within a single code block:
```python
<your code here>
```

Execution time limit: 5.0 seconds
Memory limit: 256.0 MB

# Problem
How many stars are there in the sky? A young programmer Polycarpus can't get this question out of his head! He took a photo of the starry sky using his digital camera and now he analyzes the resulting monochrome digital picture. The picture is represented by a rectangular matrix consisting of n lines each containing m characters. A character equals '1', if the corresponding photo pixel is white and '0', if it is black.

Polycarpus thinks that he has found a star on the photo if he finds a white pixel surrounded by four side-neighboring pixels that are also white:

1 111 1  a star on the photo

Polycarpus whats to cut out a rectangular area from the photo and give his mom as a present. This area should contain no less than k stars. The stars can intersect, have shared white pixels on the photo. The boy will cut out the rectangular area so that its borders will be parallel to the sides of the photo and the cuts will go straight between the pixel borders.

Now Polycarpus keeps wondering how many ways there are to cut an area out of the photo so that it met the conditions given above. Help Polycarpus find this number.

## Input Format
The first line of the input data contains three integers n, m and k (1 ≤ n, m ≤ 500;1 ≤ k ≤ nm). Then follow n lines, containing the description of the given photo as a sequence of lines. Each line contains m characters '0' or '1'.

## Output Format
Print the required number of areas on the given photo.

## Examples
```input
4 6 2
111000
111100
011011
000111
```
```output
6
```
-----
```input
5 5 4
11111
11111
11111
11111
11111
```
```output
9
```

## Note
We'll number the rows and columns below starting from 1, the coordinates (p, q) will denote a cell in row p, column q.

In the first sample Polycarpus should cut out any area containing a rectangle whose opposite corners lie in cells (1, 1) and (3, 4). Only rectangles with opposite corners in (1, 1) and (x, y), where x ≥ 3 and y ≥ 4 fit the conditions.

In the second sample any rectangle whose each side is no less than four, will do. The possible rectangle sizes are 4 × 4, 4 × 5, 5 × 4 and 5 × 5. Such figures can be cut in 4 ways, 2 ways, 2 ways and 1 way correspondingly.

Please do not use the %lld specificator to read or write 64-bit integers in C++. It is preferred to use cin, cout streams or the %I64d specificator.

Now solve the problem and return the code.
You are an expert competitive programmer. You will be given a problem statement, test case constraints and example test inputs and outputs. Please reason step by step about the solution (that must respect memory and time limits), then provide a complete implementation in python3.

Your solution must read input from standard input (cin), write output to standard output (cout).
Do not include any debug prints or additional output.

Put your final solution within a single code block:
```python
<your code here>
```

Execution time limit: 1.0 seconds
Memory limit: 256.0 MB

# Problem
You have integer $$$n$$$. Calculate how many ways are there to fully cover belt-like area of $$$4n-2$$$ triangles with diamond shapes.

Diamond shape consists of two triangles. You can move, rotate or flip the shape, but you cannot scale it.

$$$2$$$ coverings are different if some $$$2$$$ triangles are covered by the same diamond shape in one of them and by different diamond shapes in the other one.

Please look at pictures below for better understanding.

On the left you can see the diamond shape you will use, and on the right you can see the area you want to fill. These are the figures of the area you want to fill for $$$n = 1, 2, 3, 4$$$.

You have to answer $$$t$$$ independent test cases.

## Input Format
The first line contains a single integer $$$t$$$ ($$$1 \le t \le 10^{4}$$$) — the number of test cases.

Each of the next $$$t$$$ lines contains a single integer $$$n$$$ ($$$1 \le n \le 10^{9}$$$).

## Output Format
For each test case, print the number of ways to fully cover belt-like area of $$$4n-2$$$ triangles using diamond shape. It can be shown that under given constraints this number of ways doesn't exceed $$$10^{18}$$$.

## Examples
```input
2
2
1
```
```output
2
1
```

## Note
In the first test case, there are the following $$$2$$$ ways to fill the area:

In the second test case, there is a unique way to fill the area:

Now solve the problem and return the code.
You are an expert competitive programmer. You will be given a problem statement, test case constraints and example test inputs and outputs. Please reason step by step about the solution (that must respect memory and time limits), then provide a complete implementation in python3.

Your solution must read input from standard input (cin), write output to standard output (cout).
Do not include any debug prints or additional output.

Put your final solution within a single code block:
```python
<your code here>
```

Execution time limit: 1.0 seconds
Memory limit: 256.0 MB

# Problem
You have array of $$$n$$$ numbers $$$a_{1}, a_{2}, \ldots, a_{n}$$$.

Rearrange these numbers to satisfy $$$|a_{1} - a_{2}| \le |a_{2} - a_{3}| \le \ldots \le |a_{n-1} - a_{n}|$$$, where $$$|x|$$$ denotes absolute value of $$$x$$$. It's always possible to find such rearrangement.

Note that all numbers in $$$a$$$ are not necessarily different. In other words, some numbers of $$$a$$$ may be same.

You have to answer independent $$$t$$$ test cases.

## Input Format
The first line contains a single integer $$$t$$$ ($$$1 \le t \le 10^{4}$$$) — the number of test cases.

The first line of each test case contains single integer $$$n$$$ ($$$3 \le n \le 10^{5}$$$) — the length of array $$$a$$$. It is guaranteed that the sum of values of $$$n$$$ over all test cases in the input does not exceed $$$10^{5}$$$.

The second line of each test case contains $$$n$$$ integers $$$a_{1}, a_{2}, \ldots, a_{n}$$$ ($$$-10^{9} \le a_{i} \le 10^{9}$$$).

## Output Format
For each test case, print the rearranged version of array $$$a$$$ which satisfies given condition. If there are multiple valid rearrangements, print any of them.

## Examples
```input
2
6
5 -2 4 8 6 5
4
8 1 4 2
```
```output
5 5 4 6 8 -2
1 2 4 8
```

## Note
In the first test case, after given rearrangement, $$$|a_{1} - a_{2}| = 0 \le |a_{2} - a_{3}| = 1 \le |a_{3} - a_{4}| = 2 \le |a_{4} - a_{5}| = 2 \le |a_{5} - a_{6}| = 10$$$. There are other possible answers like "5 4 5 6 -2 8".

In the second test case, after given rearrangement, $$$|a_{1} - a_{2}| = 1 \le |a_{2} - a_{3}| = 2 \le |a_{3} - a_{4}| = 4$$$. There are other possible answers like "2 4 8 1".

Now solve the problem and return the code.