#D10961. Piling Up

    ID: 9109 Type: Default 2000ms 268MiB

Piling Up

Piling Up

Joisino has a lot of red and blue bricks and a large box. She will build a tower of these bricks in the following manner.

First, she will pick a total of N bricks and put them into the box. Here, there may be any number of bricks of each color in the box, as long as there are N bricks in total. Particularly, there may be zero red bricks or zero blue bricks. Then, she will repeat an operation M times, which consists of the following three steps:

  • Take out an arbitrary brick from the box.
  • Put one red brick and one blue brick into the box.
  • Take out another arbitrary brick from the box.

After the M operations, Joisino will build a tower by stacking the 2 \times M bricks removed from the box, in the order they are taken out. She is interested in the following question: how many different sequences of colors of these 2 \times M bricks are possible? Write a program to find the answer. Since it can be extremely large, print the count modulo 10^9+7.

Constraints

  • 1 \leq N \leq 3000
  • 1 \leq M \leq 3000

Input

Input is given from Standard Input in the following format:

N M

Output

Print the count of the different possible sequences of colors of 2 \times M bricks that will be stacked, modulo 10^9+7.

Examples

Input

2 3

Output

56

Input

1000 10

Output

1048576

Input

1000 3000

Output

693347555

inputFormat

Input

Input is given from Standard Input in the following format:

N M

outputFormat

Output

Print the count of the different possible sequences of colors of 2 \times M bricks that will be stacked, modulo 10^9+7.

Examples

Input

2 3

Output

56

Input

1000 10

Output

1048576

Input

1000 3000

Output

693347555

样例

1000 3000
693347555