Counting paths

Every afternoon Jack runs from his house to John's house. Both houses sit in an open field of N rows and M columns. Jack wants to take a different route every day, but he does not know how many different routes exist.

The field is written as a grid of N rows and M columns.

....
..X.
....

Jack lives in the top-left cell and John lives in the bottom-right cell. Jack does not want to waste time, so he only walks down or right. Some cells of the field hold an obstacle such as a rock or a building, and Jack cannot pass through them. An obstacle is marked with an X.

The field above has 4 valid routes. The cells that a route passes through are marked with an asterisk.

****      *...      *...      **..
..X*      *.X.      **X.      .*X.
...*      ****      .***      .***

Every valid route has the same length, N + M - 1.

The number of routes can be very large, so print it modulo 1000000007 ($10^9 + 7$).

The first line contains two integers N and M, the number of rows and the number of columns of the field.

Each of the next N lines contains M characters. A dot (.) means the cell is empty. An X means the cell holds an obstacle and Jack cannot use it.

The top-left cell and the bottom-right cell never hold an obstacle.

$2 \le N \le 200$

$2 \le M \le 200$

Print the number of routes from the top-left cell to the bottom-right cell, modulo 1000000007.

In most languages the modulus operator is %.