use std::io::Read;

fn run() {
    let mut s = String::new();
    std::io::stdin().read_to_string(&mut s).unwrap();
    let mut it = s.trim().split_whitespace();
    let h: usize = it.next().unwrap().parse().unwrap();
    let w: usize = it.next().unwrap().parse().unwrap();
    let s: Vec<Vec<char>> = it.map(|s| s.chars().collect()).collect();
    let mut dp = vec![vec![std::usize::MAX / 2; w]; h];
    dp[0][0] = 0;
    for i in 0..h {
        for j in 0..w {
            let cost = if s[i][j] == '.' {1} else {1 + i + j};
            if i > 0 {
                dp[i][j] = std::cmp::min(dp[i][j], dp[i - 1][j] + cost);
            }
            if j > 0 {
                dp[i][j] = std::cmp::min(dp[i][j], dp[i][j - 1] + cost);
            }
        }
    }
    let ans = dp[h - 1][w - 1];
    println!("{}", ans);
}

fn main() {
    run();
}