meetforever/GRPO_CL huggingface dataset:
user: Tanya has $n$ candies numbered from $1$ to $n$. The $i$-th candy has the weight $a_i$.

She plans to eat exactly $n-1$ candies and give the remaining candy to her dad. Tanya eats candies in order of increasing their numbers, exactly one candy per day.

Your task is to find the number of such candies $i$ (let's call these candies good) that if dad gets the $i$-th candy then the sum of weights of candies Tanya eats in even days will be equal to the sum of weights of candies Tanya eats in odd days. Note that at first, she will give the candy, after it she will eat the remaining candies one by one.

For example, $n=4$ and weights are $[1, 4, 3, 3]$. Consider all possible cases to give a candy to dad:  Tanya gives the $1$-st candy to dad ($a_1=1$), the remaining candies are $[4, 3, 3]$. She will eat $a_2=4$ in the first day, $a_3=3$ in the second day, $a_4=3$ in the third day. So in odd days she will eat $4+3=7$ and in even days she will eat $3$. Since $7 \ne 3$ this case shouldn't be counted to the answer (this candy isn't good).  Tanya gives the $2$-nd candy to dad ($a_2=4$), the remaining candies are $[1, 3, 3]$. She will eat $a_1=1$ in the first day, $a_3=3$ in the second day, $a_4=3$ in the third day. So in odd days she will eat $1+3=4$ and in even days she will eat $3$. Since $4 \ne 3$ this case shouldn't be counted to the answer (this candy isn't good).  Tanya gives the $3$-rd candy to dad ($a_3=3$), the remaining candies are $[1, 4, 3]$. She will eat $a_1=1$ in the first day, $a_2=4$ in the second day, $a_4=3$ in the third day. So in odd days she will eat $1+3=4$ and in even days she will eat $4$. Since $4 = 4$ this case should be counted to the answer (this candy is good).  Tanya gives the $4$-th candy to dad ($a_4=3$), the remaining candies are $[1, 4, 3]$. She will eat $a_1=1$ in the first day, $a_2=4$ in the second day, $a_3=3$ in the third day. So in odd days she will eat $1+3=4$ and in even days she will eat $4$. Since $4 = 4$ this case should be counted to the answer (this candy is good). 

In total there $2$ cases which should counted (these candies are good), so the answer is $2$.


-----Input-----

The first line of the input contains one integer $n$ ($1 \le n \le 2 \cdot 10^5$) — the number of candies.

The second line of the input contains $n$ integers $a_1, a_2, \dots, a_n$ ($1 \le a_i \le 10^4$), where $a_i$ is the weight of the $i$-th candy.


-----Output-----

Print one integer — the number of such candies $i$ (good candies) that if dad gets the $i$-th candy then the sum of weights of candies Tanya eats in even days will be equal to the sum of weights of candies Tanya eats in odd days.


-----Examples-----
Input
7
5 5 4 5 5 5 6

Output
2

Input
8
4 8 8 7 8 4 4 5

Output
2

Input
9
2 3 4 2 2 3 2 2 4

Output
3



-----Note-----

In the first example indices of good candies are $[1, 2]$.

In the second example indices of good candies are $[2, 3]$.

In the third example indices of good candies are $[4, 5, 9]$.
user: The only difference between easy and hard versions is the constraints.

Vova likes pictures with kittens. The news feed in the social network he uses can be represented as an array of $n$ consecutive pictures (with kittens, of course). Vova likes all these pictures, but some are more beautiful than the others: the $i$-th picture has beauty $a_i$.

Vova wants to repost exactly $x$ pictures in such a way that:   each segment of the news feed of at least $k$ consecutive pictures has at least one picture reposted by Vova;  the sum of beauty values of reposted pictures is maximum possible. 

For example, if $k=1$ then Vova has to repost all the pictures in the news feed. If $k=2$ then Vova can skip some pictures, but between every pair of consecutive pictures Vova has to repost at least one of them.

Your task is to calculate the maximum possible sum of values of reposted pictures if Vova follows conditions described above, or say that there is no way to satisfy all conditions.


-----Input-----

The first line of the input contains three integers $n, k$ and $x$ ($1 \le k, x \le n \le 5000$) — the number of pictures in the news feed, the minimum length of segment with at least one repost in it and the number of pictures Vova is ready to repost.

The second line of the input contains $n$ integers $a_1, a_2, \dots, a_n$ ($1 \le a_i \le 10^9$), where $a_i$ is the beauty of the $i$-th picture.


-----Output-----

Print -1 if there is no way to repost some pictures to satisfy all the conditions in the problem statement.

Otherwise print one integer — the maximum sum of values of reposted pictures if Vova follows conditions described in the problem statement.


-----Examples-----
Input
5 2 3
5 1 3 10 1

Output
18

Input
6 1 5
10 30 30 70 10 10

Output
-1

Input
4 3 1
1 100 1 1

Output
100
user: La Confiserie d'ABC sells cakes at 4 dollars each and doughnuts at 7 dollars each.
Determine if there is a way to buy some of them for exactly N dollars. You can buy two or more doughnuts and two or more cakes, and you can also choose to buy zero doughnuts or zero cakes.

-----Constraints-----
 - N is an integer between 1 and 100, inclusive.

-----Input-----
Input is given from Standard Input in the following format:
N

-----Output-----
If there is a way to buy some cakes and some doughnuts for exactly N dollars, print Yes; otherwise, print No.

-----Sample Input-----
11

-----Sample Output-----
Yes

If you buy one cake and one doughnut, the total will be 4 + 7 = 11 dollars.
user: In the Ancient Kingdom of Snuke, there was a pyramid to strengthen the authority of Takahashi, the president of AtCoder Inc.

The pyramid had center coordinates (C_X, C_Y) and height H. The altitude of coordinates (X, Y) is max(H - |X - C_X| - |Y - C_Y|, 0).  
Aoki, an explorer, conducted a survey to identify the center coordinates and height of this pyramid. As a result, he obtained the following information:  
 - C_X, C_Y was integers between 0 and 100 (inclusive), and H was an integer not less than 1.  
 - Additionally, he obtained N pieces of information. The i-th of them is: "the altitude of point (x_i, y_i) is h_i."  
This was enough to identify the center coordinates and the height of the pyramid. Find these values with the clues above.  

-----Constraints-----
 - N is an integer between 1 and 100 (inclusive).
 - x_i and y_i are integers between 0 and 100 (inclusive).
 - h_i is an integer between 0 and 10^9 (inclusive).
 - The N coordinates (x_1, y_1), (x_2, y_2), (x_3, y_3), ..., (x_N, y_N) are all different.
 - The center coordinates and the height of the pyramid can be uniquely identified.

-----Input-----
Input is given from Standard Input in the following format:  
N
x_1 y_1 h_1
x_2 y_2 h_2
x_3 y_3 h_3
:
x_N y_N h_N

-----Output-----
Print values C_X, C_Y and H representing the center coordinates and the height of the pyramid in one line, with spaces in between.  

-----Sample Input-----
4
2 3 5
2 1 5
1 2 5
3 2 5

-----Sample Output-----
2 2 6

In this case, the center coordinates and the height can be identified as (2, 2) and 6.
user: Takahashi loves palindromes. Non-palindromic strings are unacceptable to him. Each time he hugs a string, he can change one of its characters to any character of his choice.
Given is a string S. Find the minimum number of hugs needed to make S palindromic.

-----Constraints-----
 - S is a string consisting of lowercase English letters.
 - The length of S is between 1 and 100 (inclusive).

-----Input-----
Input is given from Standard Input in the following format:
S

-----Output-----
Print the minimum number of hugs needed to make S palindromic.

-----Sample Input-----
redcoder

-----Sample Output-----
1

For example, we can change the fourth character to o and get a palindrome redooder.
user: Having learned the multiplication table, Takahashi can multiply two integers between 1 and 9 (inclusive) together.
Given an integer N, determine whether N can be represented as the product of two integers between 1 and 9. If it can, print Yes; if it cannot, print No.

-----Constraints-----
 - 1 \leq N \leq 100
 - N is an integer.

-----Input-----
Input is given from Standard Input in the following format:
N

-----Output-----
If N can be represented as the product of two integers between 1 and 9 (inclusive), print Yes; if it cannot, print No.

-----Sample Input-----
10

-----Sample Output-----
Yes

10 can be represented as, for example, 2 \times 5.
user: We have sticks numbered 1, \cdots, N. The length of Stick i (1 \leq i \leq N) is L_i.
In how many ways can we choose three of the sticks with different lengths that can form a triangle?
That is, find the number of triples of integers (i, j, k) (1 \leq i < j < k \leq N) that satisfy both of the following conditions:
 - L_i, L_j, and L_k are all different.
 - There exists a triangle whose sides have lengths L_i, L_j, and L_k.

-----Constraints-----
 - 1 \leq N \leq 100
 - 1 \leq L_i \leq 10^9
 - All values in input are integers.

-----Input-----
Input is given from Standard Input in the following format:
N
L_1 L_2 \cdots L_N

-----Output-----
Print the number of ways to choose three of the sticks with different lengths that can form a triangle.

-----Sample Input-----
5
4 4 9 7 5

-----Sample Output-----
5

The following five triples (i, j, k) satisfy the conditions: (1, 3, 4), (1, 4, 5), (2, 3, 4), (2, 4, 5), and (3, 4, 5).
user: Having learned the multiplication table, Takahashi can multiply two integers between 1 and 9 (inclusive) together. He cannot do any other calculation.
Given are two integers A and B.
If Takahashi can calculate A \times B, print the result; if he cannot, print -1 instead.

-----Constraints-----
 - 1 \leq A \leq 20
 - 1 \leq B \leq 20
 - All values in input are integers.

-----Input-----
Input is given from Standard Input in the following format:
A B

-----Output-----
If Takahashi can calculate A \times B, print the result; if he cannot, print -1.

-----Sample Input-----
2 5

-----Sample Output-----
10

2 \times 5 = 10.
user: We will play a one-player game using a number line and N pieces.
First, we place each of these pieces at some integer coordinate.
Here, multiple pieces can be placed at the same coordinate.
Our objective is to visit all of the M coordinates X_1, X_2, ..., X_M with these pieces, by repeating the following move:
Move: Choose a piece and let x be its coordinate. Put that piece at coordinate x+1 or x-1.
Note that the coordinates where we initially place the pieces are already regarded as visited.
Find the minimum number of moves required to achieve the objective.

-----Constraints-----
 - All values in input are integers.
 - 1 \leq N \leq 10^5
 - 1 \leq M \leq 10^5
 - -10^5 \leq X_i \leq 10^5
 - X_1, X_2, ..., X_M are all different.

-----Input-----
Input is given from Standard Input in the following format:
N M
X_1 X_2 ... X_M

-----Output-----
Find the minimum number of moves required to achieve the objective.

-----Sample Input-----
2 5
10 12 1 2 14

-----Sample Output-----
5

The objective can be achieved in five moves as follows, and this is the minimum number of moves required.
 - Initially, put the two pieces at coordinates 1 and 10.
 - Move the piece at coordinate 1 to 2.
 - Move the piece at coordinate 10 to 11.
 - Move the piece at coordinate 11 to 12.
 - Move the piece at coordinate 12 to 13.
 - Move the piece at coordinate 13 to 14.
user: There are $n$ cities in Berland. Some pairs of cities are connected by roads. All roads are bidirectional. Each road connects two different cities. There is at most one road between a pair of cities. The cities are numbered from $1$ to $n$.

It is known that, from the capital (the city with the number $1$), you can reach any other city by moving along the roads.

The President of Berland plans to improve the country's road network. The budget is enough to repair exactly $n-1$ roads. The President plans to choose a set of $n-1$ roads such that:

  it is possible to travel from the capital to any other city along the $n-1$ chosen roads,  if $d_i$ is the number of roads needed to travel from the capital to city $i$, moving only along the $n-1$ chosen roads, then $d_1 + d_2 + \dots + d_n$ is minimized (i.e. as minimal as possible). 

In other words, the set of $n-1$ roads should preserve the connectivity of the country, and the sum of distances from city $1$ to all cities should be minimized (where you can only use the $n-1$ chosen roads).

The president instructed the ministry to prepare $k$ possible options to choose $n-1$ roads so that both conditions above are met.

Write a program that will find $k$ possible ways to choose roads for repair. If there are fewer than $k$ ways, then the program should output all possible valid ways to choose roads.


-----Input-----

The first line of the input contains integers $n$, $m$ and $k$ ($2 \le n \le 2\cdot10^5, n-1 \le m \le 2\cdot10^5, 1 \le k \le 2\cdot10^5$), where $n$ is the number of cities in the country, $m$ is the number of roads and $k$ is the number of options to choose a set of roads for repair. It is guaranteed that $m \cdot k \le 10^6$.

The following $m$ lines describe the roads, one road per line. Each line contains two integers $a_i$, $b_i$ ($1 \le a_i, b_i \le n$, $a_i \ne b_i$) — the numbers of the cities that the $i$-th road connects. There is at most one road between a pair of cities. The given set of roads is such that you can reach any city from the capital.


-----Output-----

Print $t$ ($1 \le t \le k$) — the number of ways to choose a set of roads for repair. Recall that you need to find $k$ different options; if there are fewer than $k$ of them, then you need to find all possible different valid options.

In the following $t$ lines, print the options, one per line. Print an option as a string of $m$ characters where the $j$-th character is equal to '1' if the $j$-th road is included in the option, and is equal to '0' if the road is not included. The roads should be numbered according to their order in the input. The options can be printed in any order. All the $t$ lines should be different.

Since it is guaranteed that $m \cdot k \le 10^6$, the total length of all the $t$ lines will not exceed $10^6$.

If there are several answers, output any of them.


-----Examples-----
Input
4 4 3
1 2
2 3
1 4
4 3

Output
2
1110
1011

Input
4 6 3
1 2
2 3
1 4
4 3
2 4
1 3

Output
1
101001

Input
5 6 2
1 2
1 3
2 4
2 5
3 4
3 5

Output
2
111100
110110
user: Vova's family is building the Great Vova Wall (named by Vova himself). Vova's parents, grandparents, grand-grandparents contributed to it. Now it's totally up to Vova to put the finishing touches.

The current state of the wall can be respresented by a sequence $a$ of $n$ integers, with $a_i$ being the height of the $i$-th part of the wall.

Vova can only use $2 \times 1$ bricks to put in the wall (he has infinite supply of them, however).

Vova can put bricks horizontally on the neighboring parts of the wall of equal height. It means that if for some $i$ the current height of part $i$ is the same as for part $i + 1$, then Vova can put a brick there and thus increase both heights by 1. Obviously, Vova can't put bricks in such a way that its parts turn out to be off the borders (to the left of part $1$ of the wall or to the right of part $n$ of it).

The next paragraph is specific to the version 1 of the problem.

Vova can also put bricks vertically. That means increasing height of any part of the wall by 2.

Vova is a perfectionist, so he considers the wall completed when:

  all parts of the wall has the same height;  the wall has no empty spaces inside it. 

Can Vova complete the wall using any amount of bricks (possibly zero)?


-----Input-----

The first line contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$) — the number of parts in the wall.

The second line contains $n$ integers $a_1, a_2, \dots, a_n$ ($1 \le a_i \le 10^9$) — the initial heights of the parts of the wall.


-----Output-----

Print "YES" if Vova can complete the wall using any amount of bricks (possibly zero).

Print "NO" otherwise.


-----Examples-----
Input
5
2 1 1 2 5

Output
YES

Input
3
4 5 3

Output
YES

Input
2
10 10

Output
YES

Input
3
1 2 3

Output
NO



-----Note-----

In the first example Vova can put a brick on parts 2 and 3 to make the wall $[2, 2, 2, 2, 5]$ and then put 3 bricks on parts 1 and 2 and 3 bricks on parts 3 and 4 to make it $[5, 5, 5, 5, 5]$.

In the second example Vova can put a brick vertically on part 3 to make the wall $[4, 5, 5]$, then horizontally on parts 2 and 3 to make it $[4, 6, 6]$ and then vertically on part 1 to make it $[6, 6, 6]$.

In the third example the wall is already complete.
user: A superhero fights with a monster. The battle consists of rounds, each of which lasts exactly $n$ minutes. After a round ends, the next round starts immediately. This is repeated over and over again.

Each round has the same scenario. It is described by a sequence of $n$ numbers: $d_1, d_2, \dots, d_n$ ($-10^6 \le d_i \le 10^6$). The $i$-th element means that monster's hp (hit points) changes by the value $d_i$ during the $i$-th minute of each round. Formally, if before the $i$-th minute of a round the monster's hp is $h$, then after the $i$-th minute it changes to $h := h + d_i$.

The monster's initial hp is $H$. It means that before the battle the monster has $H$ hit points. Print the first minute after which the monster dies. The monster dies if its hp is less than or equal to $0$. Print -1 if the battle continues infinitely.


-----Input-----

The first line contains two integers $H$ and $n$ ($1 \le H \le 10^{12}$, $1 \le n \le 2\cdot10^5$). The second line contains the sequence of integers $d_1, d_2, \dots, d_n$ ($-10^6 \le d_i \le 10^6$), where $d_i$ is the value to change monster's hp in the $i$-th minute of a round.


-----Output-----

Print -1 if the superhero can't kill the monster and the battle will last infinitely. Otherwise, print the positive integer $k$ such that $k$ is the first minute after which the monster is dead.


-----Examples-----
Input
1000 6
-100 -200 -300 125 77 -4

Output
9

Input
1000000000000 5
-1 0 0 0 0

Output
4999999999996

Input
10 4
-3 -6 5 4

Output
-1
user: Two-gram is an ordered pair (i.e. string of length two) of capital Latin letters. For example, "AZ", "AA", "ZA" — three distinct two-grams.

You are given a string $s$ consisting of $n$ capital Latin letters. Your task is to find any two-gram contained in the given string as a substring (i.e. two consecutive characters of the string) maximal number of times. For example, for string $s$ = "BBAABBBA" the answer is two-gram "BB", which contained in $s$ three times. In other words, find any most frequent two-gram.

Note that occurrences of the two-gram can overlap with each other.


-----Input-----

The first line of the input contains integer number $n$ ($2 \le n \le 100$) — the length of string $s$. The second line of the input contains the string $s$ consisting of $n$ capital Latin letters.


-----Output-----

Print the only line containing exactly two capital Latin letters — any two-gram contained in the given string $s$ as a substring (i.e. two consecutive characters of the string) maximal number of times.


-----Examples-----
Input
7
ABACABA

Output
AB

Input
5
ZZZAA

Output
ZZ



-----Note-----

In the first example "BA" is also valid answer.

In the second example the only two-gram "ZZ" can be printed because it contained in the string "ZZZAA" two times.
user: You are given two strings $s$ and $t$. In a single move, you can choose any of two strings and delete the first (that is, the leftmost) character. After a move, the length of the string decreases by $1$. You can't choose a string if it is empty.

For example:  by applying a move to the string "where", the result is the string "here",  by applying a move to the string "a", the result is an empty string "". 

You are required to make two given strings equal using the fewest number of moves. It is possible that, in the end, both strings will be equal to the empty string, and so, are equal to each other. In this case, the answer is obviously the sum of the lengths of the initial strings.

Write a program that finds the minimum number of moves to make two given strings $s$ and $t$ equal.


-----Input-----

The first line of the input contains $s$. In the second line of the input contains $t$. Both strings consist only of lowercase Latin letters. The number of letters in each string is between 1 and $2\cdot10^5$, inclusive.


-----Output-----

Output the fewest number of moves required. It is possible that, in the end, both strings will be equal to the empty string, and so, are equal to each other. In this case, the answer is obviously the sum of the lengths of the given strings.


-----Examples-----
Input
test
west

Output
2

Input
codeforces
yes

Output
9

Input
test
yes

Output
7

Input
b
ab

Output
1



-----Note-----

In the first example, you should apply the move once to the first string and apply the move once to the second string. As a result, both strings will be equal to "est".

In the second example, the move should be applied to the string "codeforces" $8$ times. As a result, the string becomes "codeforces" $\to$ "es". The move should be applied to the string "yes" once. The result is the same string "yes" $\to$ "es".

In the third example, you can make the strings equal only by completely deleting them. That is, in the end, both strings will be empty.

In the fourth example, the first character of the second string should be deleted.
user: There are N cities on a number line. The i-th city is located at coordinate x_i.
Your objective is to visit all these cities at least once.
In order to do so, you will first set a positive integer D.
Then, you will depart from coordinate X and perform Move 1 and Move 2 below, as many times as you like:
 - Move 1: travel from coordinate y to coordinate y + D.
 - Move 2: travel from coordinate y to coordinate y - D.
Find the maximum value of D that enables you to visit all the cities.
Here, to visit a city is to travel to the coordinate where that city is located.

-----Constraints-----
 - All values in input are integers.
 - 1 \leq N \leq 10^5
 - 1 \leq X \leq 10^9
 - 1 \leq x_i \leq 10^9
 - x_i are all different.
 - x_1, x_2, ..., x_N \neq X

-----Input-----
Input is given from Standard Input in the following format:
N X
x_1 x_2 ... x_N

-----Output-----
Print the maximum value of D that enables you to visit all the cities.

-----Sample Input-----
3 3
1 7 11

-----Sample Output-----
2

Setting D = 2 enables you to visit all the cities as follows, and this is the maximum value of such D.
 - Perform Move 2 to travel to coordinate 1.
 - Perform Move 1 to travel to coordinate 3.
 - Perform Move 1 to travel to coordinate 5.
 - Perform Move 1 to travel to coordinate 7.
 - Perform Move 1 to travel to coordinate 9.
 - Perform Move 1 to travel to coordinate 11.
user: A string S of an odd length is said to be a strong palindrome if and only if all of the following conditions are satisfied:
 - S is a palindrome.
 - Let N be the length of S. The string formed by the 1-st through ((N-1)/2)-th characters of S is a palindrome.
 - The string consisting of the (N+3)/2-st through N-th characters of S is a palindrome.
Determine whether S is a strong palindrome.

-----Constraints-----
 - S consists of lowercase English letters.
 - The length of S is an odd number between 3 and 99 (inclusive).

-----Input-----
Input is given from Standard Input in the following format:
S

-----Output-----
If S is a strong palindrome, print Yes;
otherwise, print No.

-----Sample Input-----
akasaka

-----Sample Output-----
Yes

 - S is akasaka.
 - The string formed by the 1-st through the 3-rd characters is aka.
 - The string formed by the 5-th through the 7-th characters is aka.
All of these are palindromes, so S is a strong palindrome.
user: Compute A \times B, truncate its fractional part, and print the result as an integer.

-----Constraints-----
 - 0 \leq A \leq 10^{15}
 - 0 \leq B < 10
 - A is an integer.
 - B is a number with two digits after the decimal point.

-----Input-----
Input is given from Standard Input in the following format:
A B

-----Output-----
Print the answer as an integer.

-----Sample Input-----
198 1.10

-----Sample Output-----
217

We have 198 \times 1.10 = 217.8. After truncating the fractional part, we have the answer: 217.