[AtCoder][競プロ][DP][Educational DP Contest]H-Grid 1

def main():
    import sys
    input = sys.stdin.readline
    #文字列入力の時は上記はerrorとなる。
    #ここにコード
    #input
    h, w = map(int, input().split())
    a = ["" * w for _ in range(h)]
    for i in range(h):
        a[i] = list(map(str, input().split()))

    #output
    mod = pow(10, 9) + 7

    dp = [[0]*w for _ in range(h)]
    dp[0][0] = 1

    for j in range(w):
        if a[0][0][j] == ".":
            dp[0][j] = 1
        else:
            break
    for i in range(h):
        if a[i][0][0] == ".":
            dp[i][0] = 1
        else:
            break

    for i in range(h-1):
        for j in range(w-1):
            if a[i+1][0][j+1] == "#":
                dp[i+1][j+1] = 0
            else:
                dp[i+1][j+1] = dp[i+1][j] % mod + dp[i][j+1] % mod

    print(dp[h-1][w-1] % mod)
    #N = 1のときなどcorner caseを確認！
if __name__ == "__main__":
    main()