use proconio::input;
use proconio::marker::Chars;

fn main () {
    input! {
        h: usize,
        w: usize,
        a: [Chars;h],
    }
    //println!("{:?}", a);

    let mut q : Vec<(usize, usize, i32)> = Vec::new();
    q.push((0,0,1));
    let mut ans = 0;
    while !q.is_empty() {
        let v = q.pop().unwrap();
        let x = v.0;
        let y = v.1;
        let jew = v.2;

        if x == w-1 && y == h-1 {
            ans += 1;
            continue;
        }
        if jew == -1 {
            continue;
        }
        //right
        if x+1 < w && a[x+1][y] != '#' {
            let j = if a[x+1][y] == 'o' {1} else {-1};
            q.push((x+1, y, jew+j));
        }
        if y+1 < h && a[x][y+1] != '#' {
            let j = if a[x][y+1] == 'o' {1} else {-1};
            q.push((x, y+1, jew+j));
        }
        //println!("q: {:?}", q);
    }
    println!("{}", ans);
}