Codeforces Round 195 (Div. 2)
E
Vasily the Bear and Painting Square
Codeforces
2700
原题
← D→
翻译中…

Vasily the bear has two favorite integers $*n*$ and $*k*$ and a pencil. Besides, he's got $*k*$ jars with different water color paints. All jars are numbered in some manner from $1$ to $*k*$, inclusive. The jar number $*i*$ contains the paint of the $*i*$-th color.

翻译中…

Initially the bear took a pencil and drew four segments on the coordinate plane. All of them end at point $(0, 0)$. They begin at: $(0, 2^{*n*})$, $(0,  - 2^{*n*})$, $(2^{*n*}, 0)$, $( - 2^{*n*}, 0)$. Then for each $*i* = 1, 2, ..., *n*$, the bear drew two squares. The first square has the following vertex coordinates: $(2^{*i*}, 0)$, $( - 2^{*i*}, 0)$, $(0,  - 2^{*i*})$, $(0, 2^{*i*})$. The second square has the following vertex coordinates: $( - 2^{*i* - 1},  - 2^{*i* - 1})$, $( - 2^{*i* - 1}, 2^{*i* - 1})$, $(2^{*i* - 1},  - 2^{*i* - 1})$, $(2^{*i* - 1}, 2^{*i* - 1})$. After that, the bear drew another square: $(1, 0)$, $( - 1, 0)$, $(0,  - 1)$, $(0, 1)$. All points mentioned above form the set of points $*A*$.

翻译中…

image

翻译中…

The sample of the final picture at $*n* = 0$

翻译中…

image

翻译中…

The sample of the final picture at $*n* = 2$

翻译中…

The bear decided to paint the resulting picture in $*k*$ moves. The $*i*$-th move consists of the following stages:

翻译中…
  1. The bear chooses 3 distinct points in set $*А*$ so that any pair of the chosen points has a segment on the picture between them. The chosen points and segments mark the area that mustn't contain any previously painted points.
  2. The bear paints the area bounded by the chosen points and segments the $*i*$-th color.
翻译中…

Note that after the $*k*$-th move some parts of the picture can stay unpainted.

翻译中…

The bear asked you to calculate, how many distinct ways there are to paint his picture. A way to paint the picture is a sequence of three-element sets of points he chose on each step. Two sequences are considered distinct if there is such number $*i*$ ($1 ≤ *i* ≤ *k*)$, that the $*i*$-th members of these sequences do not coincide as sets. As the sought number can be rather large, you only need to calculate the remainder after dividing it by number $1000000007$ ($10^{9} + 7$).

翻译中…

Input

翻译中…

The first line contains two integers $*n*$ and $*k*$, separated by a space ($0 ≤ *n*, *k* ≤ 200$).

翻译中…

Output

翻译中…

Print exactly one integer — the answer to the problem modulo $1000000007$ ($10^{9} + 7$).

翻译中…

样例

Input #1
0 0
Output #1
1
InputCopy OutputCopy
Input #2
0 1
Output #2
8
InputCopy OutputCopy
Input #3
0 2
Output #3
32
InputCopy OutputCopy
Input #4
1 1
Output #4
32
InputCopy OutputCopy
题目信息
题号
336E
时间限制
2 s
内存限制
256 MB
标签
位运算
组合数学
动态规划
模拟

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。