Problem Statement

Snuke is interested in strings that satisfy the following conditions:

• The length of the string is at least N.
• The first N characters equal to the string s.
• The last N characters equal to the string t.

Find the length of the shortest string that satisfies the conditions.

Constraints

• 1≤N≤100
• The lengths of s and t are both N.
• s and t consist of lowercase English letters.

Sample Input 1

3
abc
cde

Sample Output 1

5

The shortest string is abcde.

Sample Input 2

1
a
z

Sample Output 2

2

The shortest string is az.

Sample Input 3

4
expr
expr

Sample Output 3

4

The shortest string is expr.

Problem Statement

We have a pyramid with N steps, built with blocks. The steps are numbered 1 through N from top to bottom. For each 1≤i≤N, step i consists of 2i-1 blocks aligned horizontally. The pyramid is built so that the blocks at the centers of the steps are aligned vertically.

A pyramid with N=4 steps

Snuke wrote a permutation of (1, 2, ..., 2N-1) into the blocks of step N. Then, he wrote integers into all remaining blocks, under the following rule:

• The integer written into a block b must be equal to the median of the three integers written into the three blocks directly under b, or to the lower left or lower right of b.

Writing integers into the blocks

Afterwards, he erased all integers written into the blocks. Now, he only remembers that the integer written into the block of step 1 was x.

Construct a permutation of (1, 2, ..., 2N-1) that could have been written into the blocks of step N, or declare that Snuke's memory is incorrect and such a permutation does not exist.

Constraints

• 2≤N≤10^5
• 1≤x≤2N-1

Sample Input 1

4 4

Sample Output 1

Yes
1
6
3
7
4
5
2

This case corresponds to the figure in the problem statement.

Sample Input 2

2 1

Sample Output 2

No

No matter what permutation was written into the blocks of step N, the integer written into the block of step 1 would be 2.

Problem Statement

There are N rabbits on a number line. The rabbits are conveniently numbered 1 through N. The coordinate of the initial position of rabbit i is x_i.

The rabbits will now take exercise on the number line, by performing sets described below. A set consists of M jumps. The j-th jump of a set is performed by rabbit a_j (2≤a_j≤N-1). For this jump, either rabbit a_j-1 or rabbit a_j+1 is chosen with equal probability (let the chosen rabbit be rabbit x), then rabbit a_j will jump to the symmetric point of its current position with respect to rabbit x.

The rabbits will perform K sets in succession. For each rabbit, find the expected value of the coordinate of its eventual position after K sets are performed.

Constraints

• 3≤N≤10^5
• x_i is an integer.
• |x_i|≤10^9
• 1≤M≤10^5
• 2≤a_j≤N-1
• 1≤K≤10^{18}

Sample Input 1

3
-1 0 2
1 1
2

Sample Output 1

-1.0
1.0
2.0

Rabbit 2 will perform the jump. If rabbit 1 is chosen, the coordinate of the destination will be -2. If rabbit 3 is chosen, the coordinate of the destination will be 4. Thus, the expected value of the coordinate of the eventual position of rabbit 2 is 0.5×(-2)+0.5×4=1.0.

Sample Input 2

3
1 -1 1
2 2
2 2

Sample Output 2

1.0
-1.0
1.0

x_i may not be distinct.

Sample Input 3

5
0 1 3 6 10
3 10
2 3 4

Sample Output 3

0.0
3.0
7.0
8.0
10.0

Problem Statement

We have a pyramid with N steps, built with blocks. The steps are numbered 1 through N from top to bottom. For each 1≤i≤N, step i consists of 2i-1 blocks aligned horizontally. The pyramid is built so that the blocks at the centers of the steps are aligned vertically.

A pyramid with N=4 steps

Snuke wrote a permutation of (1, 2, ..., 2N-1) into the blocks of step N. Then, he wrote integers into all remaining blocks, under the following rule:

• The integer written into a block b must be equal to the median of the three integers written into the three blocks directly under b, or to the lower left or lower right of b.

Writing integers into the blocks

Afterwards, he erased all integers written into the blocks. Now, he only remembers that the permutation written into the blocks of step N was (a_1, a_2, ..., a_{2N-1}).

Find the integer written into the block of step 1.

Constraints

• 2≤N≤10^5
• (a_1, a_2, ..., a_{2N-1}) is a permutation of (1, 2, ..., 2N-1).

Sample Input 1

4
1 6 3 7 4 5 2

Sample Output 1

4

This case corresponds to the figure in the problem statement.

Sample Input 2

2
1 2 3

Sample Output 2

2

Problem Statement

We have a grid with 3 rows and N columns. The cell at the i-th row and j-th column is denoted (i, j). Initially, each cell (i, j) contains the integer i+3j-3.

A grid with N=5 columns

Snuke can perform the following operation any number of times:

• Choose a 3×3 subrectangle of the grid. The placement of integers within the subrectangle is now rotated by 180°.

An example sequence of operations (each chosen subrectangle is colored blue)

Snuke's objective is to manipulate the grid so that each cell (i, j) contains the integer a_{i,j}. Determine whether it is achievable.

Constraints

• 5≤N≤10^5
• 1≤a_{i,j}≤3N
• All a_{i,j} are distinct.

Sample Input 1

5
9 6 15 12 1
8 5 14 11 2
7 4 13 10 3

Sample Output 1

Yes

This case corresponds to the figure in the problem statement.

Sample Input 2

5
1 2 3 4 5
6 7 8 9 10
11 12 13 14 15

Sample Output 2

No

Sample Input 3

5
1 4 7 10 13
2 5 8 11 14
3 6 9 12 15

Sample Output 3

Yes

The objective is already achieved with the initial placement of the integers.

Sample Input 4

6
15 10 3 4 9 16
14 11 2 5 8 17
13 12 1 6 7 18

Sample Output 4

Yes

Sample Input 5

7
21 12 1 16 13 6 7
20 11 2 17 14 5 8
19 10 3 18 15 4 9

Sample Output 5

No

Problem Statement

We have a grid with N rows and N columns. The cell at the i-th row and j-th column is denoted (i, j).

Initially, M of the cells are painted black, and all other cells are white. Specifically, the cells (a_1, b_1), (a_2, b_2), ..., (a_M, b_M) are painted black.

Snuke will try to paint as many white cells black as possible, according to the following rule:

• If two cells (x, y) and (y, z) are both black and a cell (z, x) is white for integers 1≤x,y,z≤N, paint the cell (z, x) black.

Find the number of black cells when no more white cells can be painted black.

Constraints

• 1≤N≤10^5
• 1≤M≤10^5
• 1≤a_i,b_i≤N
• All pairs (a_i, b_i) are distinct.

Sample Input 1

3 2
1 2
2 3

Sample Output 1

3

It is possible to paint one white cell black, as follows:

• Since cells (1, 2) and (2, 3) are both black and a cell (3, 1) is white, paint the cell (3, 1) black.

Sample Input 2

2 2
1 1
1 2

Sample Output 2

4

It is possible to paint two white cells black, as follows:

• Since cells (1, 1) and (1, 2) are both black and a cell (2, 1) is white, paint the cell (2, 1) black.
• Since cells (2, 1) and (1, 2) are both black and a cell (2, 2) is white, paint the cell (2, 2) black.

Sample Input 3

4 3
1 2
1 3
4 4

Sample Output 3

3

No white cells can be painted black.