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: 1.0 seconds
Memory limit: 64.0 MB

# Problem
Once Bob took a paper stripe of n squares (the height of the stripe is 1 square). In each square he wrote an integer number, possibly negative. He became interested in how many ways exist to cut this stripe into three pieces so that the sum of numbers from each piece is equal to the sum of numbers from any other piece, and each piece contains positive integer amount of squares. Would you help Bob solve this problem?

## Input Format
The first input line contains integer n (1 ≤ n ≤ 105) — amount of squares in the stripe. The second line contains n space-separated numbers — they are the numbers written in the squares of the stripe. These numbers are integer and do not exceed 10000 in absolute value.

## Output Format
Output the amount of ways to cut the stripe into three non-empty pieces so that the sum of numbers from each piece is equal to the sum of numbers from any other piece. Don't forget that it's allowed to cut the stripe along the squares' borders only.

## Examples
```input
4
1 2 3 3
```
```output
1
```
-----
```input
5
1 2 3 4 5
```
```output
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: 0.5 seconds
Memory limit: 64.0 MB

# Problem
You are given undirected weighted graph. Find the length of the shortest cycle which starts from the vertex 1 and passes throught all the edges at least once. Graph may contain multiply edges between a pair of vertices and loops (edges from the vertex to itself).

## Input Format
The first line of the input contains two integers n and m (1 ≤ n ≤ 15, 0 ≤ m ≤ 2000), n is the amount of vertices, and m is the amount of edges. Following m lines contain edges as a triples x, y, w (1 ≤ x, y ≤ n, 1 ≤ w ≤ 10000), x, y are edge endpoints, and w is the edge length.

## Output Format
Output minimal cycle length or -1 if it doesn't exists.

## Examples
```input
3 3
1 2 1
2 3 1
3 1 1
```
```output
3
```
-----
```input
3 2
1 2 3
2 3 4
```
```output
14
```

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: 3.0 seconds
Memory limit: 256.0 MB

# Problem
The Little Elephant is playing with the Cartesian coordinates' system. Most of all he likes playing with integer points. The Little Elephant defines an integer point as a pair of integers (x; y), such that 0 ≤ x ≤ w and 0 ≤ y ≤ h. Thus, the Little Elephant knows only (w + 1)·(h + 1) distinct integer points.

The Little Elephant wants to paint a triangle with vertexes at integer points, the triangle's area must be a positive integer. For that, he needs to find the number of groups of three points that form such triangle. At that, the order of points in a group matters, that is, the group of three points (0;0), (0;2), (2;2) isn't equal to the group (0;2), (0;0), (2;2).

Help the Little Elephant to find the number of groups of three integer points that form a nondegenerate triangle with integer area.

## Input Format
A single line contains two integers w and h (1 ≤ w, h ≤ 4000).

## Output Format
In a single output line print an integer — the remainder of dividing the answer to the problem by 1000000007 (109 + 7).

## Examples
```input
2 1
```
```output
36
```
-----
```input
2 2
```
```output
240
```

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 soluton must read input from the file 'input.txt' and write output to the file 'output.txt'.
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
One fine October day a mathematics teacher Vasily Petrov went to a class and saw there n pupils who sat at the $$\frac{\pi}{2}$$ desks, two people at each desk. Vasily quickly realized that number n is even. Like all true mathematicians, Vasily has all students numbered from 1 to n.

But Vasily Petrov did not like the way the children were seated at the desks. According to him, the students whose numbers differ by 1, can not sit together, as they talk to each other all the time, distract others and misbehave.

On the other hand, if a righthanded student sits at the left end of the desk and a lefthanded student sits at the right end of the desk, they hit elbows all the time and distract each other. In other cases, the students who sit at the same desk, do not interfere with each other.

Vasily knows very well which students are lefthanders and which ones are righthanders, and he asks you to come up with any order that meets these two uncomplicated conditions (students do not talk to each other and do not bump their elbows). It is guaranteed that the input is such that at least one way to seat the students always exists.

## Input Format
The first input line contains a single even integer n (4 ≤ n ≤ 100) — the number of students in the class. The second line contains exactly n capital English letters "L" and "R". If the i-th letter at the second line equals "L", then the student number i is a lefthander, otherwise he is a righthander.

## Output Format
Print $$\frac{\pi}{2}$$ integer pairs, one pair per line. In the i-th line print the numbers of students that will sit at the i-th desk. The first number in the pair stands for the student who is sitting to the left, and the second number stands for the student who is sitting to the right. Separate the numbers in the pairs by spaces. If there are multiple solutions, print any of them.

## Examples
```input
6
LLRLLL
```
```output
1 4
2 5
6 3
```
-----
```input
4
RRLL
```
```output
3 1
4 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 soluton must read input from the file 'input.txt' and write output to the file 'output.txt'.
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
Vasya is going to the Olympics in the city Ntown by train. The boy wants to read the textbook to prepare for the Olympics. He counted that he needed k hours for this. He also found that the light in the train changes every hour. The light is measured on a scale from 0 to 100, where 0 is very dark, and 100 is very light.

Vasya has a train lighting schedule for all n hours of the trip — n numbers from 0 to 100 each (the light level in the first hour, the second hour and so on). During each of those hours he will either read the whole time, or not read at all. He wants to choose k hours to read a book, not necessarily consecutive, so that the minimum level of light among the selected hours were maximum. Vasya is very excited before the upcoming contest, help him choose reading hours.

## Input Format
The first input line contains two integers n and k (1 ≤ n ≤ 1000, 1 ≤ k ≤ n) — the number of hours on the train and the number of hours to read, correspondingly. The second line contains n space-separated integers ai (0 ≤ ai ≤ 100), ai is the light level at the i-th hour.

## Output Format
In the first output line print the minimum light level Vasya will read at. In the second line print k distinct space-separated integers b1, b2, ..., bk, — the indexes of hours Vasya will read at (1 ≤ bi ≤ n). The hours are indexed starting from 1. If there are multiple optimal solutions, print any of them. Print the numbers bi in an arbitrary order.

## Examples
```input
5 3
20 10 30 40 10
```
```output
20
1 3 4
```
-----
```input
6 5
90 20 35 40 60 100
```
```output
35
1 3 4 5 6
```

## Note
In the first sample Vasya should read at the first hour (light 20), third hour (light 30) and at the fourth hour (light 40). The minimum light Vasya will have to read at is 20.

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 is a programming language in which every program is a non-empty sequence of "<" and ">" signs and digits. Let's explain how the interpreter of this programming language works. A program is interpreted using movement of instruction pointer (IP) which consists of two parts.

- Current character pointer (CP);
- Direction pointer (DP) which can point left or right;

Initially CP points to the leftmost character of the sequence and DP points to the right.

We repeat the following steps until the first moment that CP points to somewhere outside the sequence.

- If CP is pointing to a digit the interpreter prints that digit then CP moves one step according to the direction of DP. After that the value of the printed digit in the sequence decreases by one. If the printed digit was 0 then it cannot be decreased therefore it's erased from the sequence and the length of the sequence decreases by one.
- If CP is pointing to "<" or ">" then the direction of DP changes to "left" or "right" correspondingly. Then CP moves one step according to DP. If the new character that CP is pointing to is "<" or ">" then the previous character will be erased from the sequence.

If at any moment the CP goes outside of the sequence the execution is terminated.

It's obvious the every program in this language terminates after some steps.

We have a sequence s1, s2, ..., sn of "<", ">" and digits. You should answer q queries. Each query gives you l and r and asks how many of each digit will be printed if we run the sequence sl, sl + 1, ..., sr as an independent program in this language.

## Input Format
The first line of input contains two integers n and q (1 ≤ n, q ≤ 105) — represents the length of the sequence s and the number of queries.

The second line contains s, a sequence of "<", ">" and digits (0..9) written from left to right. Note, that the characters of s are not separated with spaces.

The next q lines each contains two integers li and ri (1 ≤ li ≤ ri ≤ n) — the i-th query.

## Output Format
For each query print 10 space separated integers: x0, x1, ..., x9 where xi equals the number of times the interpreter prints i while running the corresponding program. Print answers to the queries in the order they are given in input.

## Examples
```input
7 4
1>3>22<
1 3
4 7
7 7
1 7
```
```output
0 1 0 1 0 0 0 0 0 0
2 2 2 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0
2 3 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: 2.0 seconds
Memory limit: 256.0 MB

# Problem
Urpal lives in a big city. He has planned to meet his lover tonight.

The city has n junctions numbered from 1 to n. The junctions are connected by m directed streets, all the roads have equal length. Urpal lives in junction a and the date is planned in a restaurant in junction b. He wants to use public transportation to get to junction b. There are k bus transportation companies. At the beginning of every second, a bus from the i-th company chooses a random shortest path between junction si and junction ti and passes through it. There might be no path from si to ti. In that case no bus will leave from si to ti. If a bus passes through a junction where Urpal stands, he can get on the bus. He can also get off the bus at any junction along the path.

Now Urpal wants to know if it's possible to go to the date using public transportation in a finite amount of time (the time of travel is the sum of length of the traveled roads) and what is the minimum number of buses he should take in the worst case.

At any moment Urpal knows only his own position and the place where the date will be. When he gets on the bus he knows only the index of the company of this bus. Of course Urpal knows the city map and the the pairs (si, ti) for each company.

Note that Urpal doesn't know buses velocity.

## Input Format
The first line of the input contains four integers n, m, a, b (2 ≤ n ≤ 100; 0 ≤ m ≤ n·(n - 1); 1 ≤ a, b ≤ n; a ≠ b).

The next m lines contain two integers each ui and vi (1 ≤ ui, vi ≤ n; ui ≠ vi) describing a directed road from junction ui to junction vi. All roads in the input will be distinct.

The next line contains an integer k (0 ≤ k ≤ 100). There will be k lines after this, each containing two integers si and ti (1 ≤ si, ti ≤ n; si ≠ ti) saying there is a bus route starting at si and ending at ti. Please note that there might be no path from si to ti, this case is described in the problem statement.

## Output Format
In the only line of output print the minimum number of buses Urpal should get on on his way in the worst case. If it's not possible to reach the destination in the worst case print -1.

## Examples
```input
7 8 1 7
1 2
1 3
2 4
3 4
4 6
4 5
6 7
5 7
3
2 7
1 4
5 7
```
```output
2
```
-----
```input
4 4 1 2
1 2
1 3
2 4
3 4
1
1 4
```
```output
-1
```

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
Petya and Vasya are tossing a coin. Their friend Valera is appointed as a judge. The game is very simple. First Vasya tosses a coin x times, then Petya tosses a coin y times. If the tossing player gets head, he scores one point. If he gets tail, nobody gets any points. The winner is the player with most points by the end of the game. If boys have the same number of points, the game finishes with a draw.

At some point, Valera lost his count, and so he can not say exactly what the score is at the end of the game. But there are things he remembers for sure. He remembers that the entire game Vasya got heads at least a times, and Petya got heads at least b times. Moreover, he knows that the winner of the game was Vasya. Valera wants to use this information to know every possible outcome of the game, which do not contradict his memories.

## Input Format
The single line contains four integers x, y, a, b (1 ≤ a ≤ x ≤ 100, 1 ≤ b ≤ y ≤ 100). The numbers on the line are separated by a space.

## Output Format
In the first line print integer n — the number of possible outcomes of the game. Then on n lines print the outcomes. On the i-th line print a space-separated pair of integers ci, di — the number of heads Vasya and Petya got in the i-th outcome of the game, correspondingly. Print pairs of integers (ci, di) in the strictly increasing order.

Let us remind you that the pair of numbers (p1, q1) is less than the pair of numbers (p2, q2), if p1 < p2, or p1 = p2 and also q1 < q2.

## Examples
```input
3 2 1 1
```
```output
3
2 1
3 1
3 2
```
-----
```input
2 4 2 2
```
```output
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: 2.0 seconds
Memory limit: 256.0 MB

# Problem
A coordinate line has n segments, the i-th segment starts at the position li and ends at the position ri. We will denote such a segment as [li, ri].

You have suggested that one of the defined segments covers all others. In other words, there is such segment in the given set, which contains all other ones. Now you want to test your assumption. Find in the given set the segment which covers all other segments, and print its number. If such a segment doesn't exist, print -1.

Formally we will assume that segment [a, b] covers segment [c, d], if they meet this condition a ≤ c ≤ d ≤ b.

## Input Format
The first line contains integer n (1 ≤ n ≤ 105) — the number of segments. Next n lines contain the descriptions of the segments. The i-th line contains two space-separated integers li, ri (1 ≤ li ≤ ri ≤ 109) — the borders of the i-th segment.

It is guaranteed that no two segments coincide.

## Output Format
Print a single integer — the number of the segment that covers all other segments in the set. If there's no solution, print -1.

The segments are numbered starting from 1 in the order in which they appear in the input.

## Examples
```input
3
1 1
2 2
3 3
```
```output
-1
```
-----
```input
6
1 5
2 3
1 10
7 10
7 7
10 10
```
```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
The black king is standing on a chess field consisting of 109 rows and 109 columns. We will consider the rows of the field numbered with integers from 1 to 109 from top to bottom. The columns are similarly numbered with integers from 1 to 109 from left to right. We will denote a cell of the field that is located in the i-th row and j-th column as (i, j).

You know that some squares of the given chess field are allowed. All allowed cells of the chess field are given as n segments. Each segment is described by three integers ri, ai, bi (ai ≤ bi), denoting that cells in columns from number ai to number bi inclusive in the ri-th row are allowed.

Your task is to find the minimum number of moves the king needs to get from square (x0, y0) to square (x1, y1), provided that he only moves along the allowed cells. In other words, the king can be located only on allowed cells on his way.

Let us remind you that a chess king can move to any of the neighboring cells in one move. Two cells of a chess field are considered neighboring if they share at least one point.

## Input Format
The first line contains four space-separated integers x0, y0, x1, y1 (1 ≤ x0, y0, x1, y1 ≤ 109), denoting the initial and the final positions of the king.

The second line contains a single integer n (1 ≤ n ≤ 105), denoting the number of segments of allowed cells. Next n lines contain the descriptions of these segments. The i-th line contains three space-separated integers ri, ai, bi (1 ≤ ri, ai, bi ≤ 109, ai ≤ bi), denoting that cells in columns from number ai to number bi inclusive in the ri-th row are allowed. Note that the segments of the allowed cells can intersect and embed arbitrarily.

It is guaranteed that the king's initial and final position are allowed cells. It is guaranteed that the king's initial and the final positions do not coincide. It is guaranteed that the total length of all given segments doesn't exceed 105.

## Output Format
If there is no path between the initial and final position along allowed cells, print -1.

Otherwise print a single integer — the minimum number of moves the king needs to get from the initial position to the final one.

## Examples
```input
5 7 6 11
3
5 3 8
6 7 11
5 2 5
```
```output
4
```
-----
```input
3 4 3 10
3
3 1 4
4 5 9
3 10 10
```
```output
6
```
-----
```input
1 1 2 10
2
1 1 3
2 6 10
```
```output
-1
```

Now solve the problem and return the code.