Dima loves making pictures on a piece of squared paper. And yet more than that Dima loves the pictures that depict one of his favorite figures. A piece of squared paper of size n × m is represented by a table, consisting of n rows and m columns. All squares are white on blank squared paper. Dima defines a picture as an image on a blank piece of paper, obtained by painting some squares black. The picture portrays one of Dima's favorite figures, if the following conditions hold: The picture contains at least one painted cell; All painted cells form a connected set, that is, you can get from any painted cell to any other one (you can move from one cell to a side-adjacent one); The minimum number of moves needed to go from the painted cell at coordinates (x 1, y 1) to the painted cell at coordinates (x 2, y 2), moving only through the colored cells, equals x 1 - x 2 + y 1 - y 2. Now Dima is wondering: how many paintings are on an n × m piece of paper, that depict one of his favorite figures? Count this number modulo 1000000007 (109 + 7).

输入描述:

The first line contains two integers n and m — the sizes of the piece of paper (1 ≤ n, m ≤ 150).

输出描述:

In a single line print the remainder after dividing the answer to the problem by number 1000000007 (109 + 7).