{"raw_statement":[{"iden":"problem statement","content":"There is a grid with $H$ horizontal rows and $W$ vertical columns. Let $(i, j)$ denote the square at the $i$\\-th row from the top and the $j$\\-th column from the left.\nFor each $i$ and $j$ ($1 \\leq i \\leq H$, $1 \\leq j \\leq W$), Square $(i, j)$ is described by a character $a_{i, j}$. If $a_{i, j}$ is `.`, Square $(i, j)$ is an empty square; if $a_{i, j}$ is `#`, Square $(i, j)$ is a wall square. It is guaranteed that Squares $(1, 1)$ and $(H, W)$ are empty squares.\nTaro will start from Square $(1, 1)$ and reach $(H, W)$ by repeatedly moving right or down to an adjacent empty square.\nFind the number of Taro's paths from Square $(1, 1)$ to $(H, W)$. As the answer can be extremely large, find the count modulo $10^9 + 7$."},{"iden":"constraints","content":"*   $H$ and $W$ are integers.\n*   $2 \\leq H, W \\leq 1000$\n*   $a_{i, j}$ is `.` or `#`.\n*   Squares $(1, 1)$ and $(H, W)$ are empty squares."},{"iden":"input","content":"Input is given from Standard Input in the following format:\n\n$H$ $W$\n$a_{1, 1}$$\\ldots$$a_{1, W}$\n$:$\n$a_{H, 1}$$\\ldots$$a_{H, W}$"},{"iden":"sample input 1","content":"3 4\n...#\n.#..\n...."},{"iden":"sample output 1","content":"3\n\nThere are three paths as follows:\n![image](https://img.atcoder.jp/dp/grid_0_0_muffet.png)"},{"iden":"sample input 2","content":"5 2\n..\n#.\n..\n.#\n.."},{"iden":"sample output 2","content":"0\n\nThere may be no paths."},{"iden":"sample input 3","content":"5 5\n..#..\n.....\n#...#\n.....\n..#.."},{"iden":"sample output 3","content":"24"},{"iden":"sample input 4","content":"20 20\n....................\n....................\n....................\n....................\n....................\n....................\n....................\n....................\n....................\n....................\n....................\n....................\n....................\n....................\n....................\n....................\n....................\n....................\n....................\n...................."},{"iden":"sample output 4","content":"345263555\n\nBe sure to print the count modulo $10^9 + 7$."}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}