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 i = v.0;
        let j = v.1;
        let jew = v.2;
        //println!("{:?}", v);

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