fn dfs(current: &mut Vec<usize>, cnt: &mut usize, lim: usize) -> usize {
    if current.len() == lim {
        return *cnt;
    }
    let mut result = 0;
    for i in 1..=lim {
        if current.contains(&i) {
            continue;
        } else if current[current.len()-1] < i || *cnt == 0 as usize {
            if current[current.len()-1] > i { *cnt += 1; }
            current.push(i);
            result += dfs(current, cnt, lim);
            current.pop();
            if current[current.len()-1] > i { *cnt -= 1; }
        }
    }
    result
}

fn main() {
    let mut nk = String::new();
    std::io::stdin().read_line(&mut nk).ok();
    let nk: Vec<usize> = nk.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let n = nk[0];
    let k = nk[1];

    let mut base: Vec<usize> = vec![k; 1];
    let mut cnt = 0;
    let result = dfs(&mut base, &mut cnt, n);
    println!("{}", result);
}