macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        let mut next = || { iter.next().unwrap() };
        input_inner!{next, $($r)*}
    };
    ($($r:tt)*) => {
        let stdin = std::io::stdin();
        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
        let mut next = move || -> String{
            bytes
                .by_ref()
                .map(|r|r.unwrap() as char)
                .skip_while(|c|c.is_whitespace())
                .take_while(|c|!c.is_whitespace())
                .collect()
        };
        input_inner!{next, $($r)*}
    };
}

macro_rules! input_inner {
    ($next:expr) => {};
    ($next:expr, ) => {};

    ($next:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };
}

macro_rules! read_value {
    ($next:expr, ( $($t:tt),* )) => {
        ( $(read_value!($next, $t)),* )
    };

    ($next:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
    };

    ($next:expr, chars) => {
        read_value!($next, String).chars().collect::<Vec<char>>()
    };

    ($next:expr, usize1) => {
        read_value!($next, usize) - 1
    };

    ($next:expr, $t:ty) => {
        $next().parse::<$t>().expect("Parse error")
    };
}

fn calc_comb(n: usize, r: usize) -> usize {
    let mut num = 1;
    for i in 1..=r {
        num = num * (n - i + 1) / i;
    }
    num
}

fn main() {
    input! {
    n: chars,
    k: usize,
    }
    let n = n.iter().map(|x| x.to_digit(10).unwrap() as usize).collect::<Vec<usize>>();
    let mut l = n.len();
    let mut k = k;
    let mut ans = 0;
    for i in n {
        // 0
        if k == 0 {break};
        if l >= k + 1 {
            ans += 9usize.pow(k as u32) * calc_comb(l - 1, k);
        }
        // 1 ~ i - 1
        ans += 9usize.pow((k -1) as u32) * calc_comb(l - 1, k - 1) * (i - 1);
        l -= 1;
        k -= 1;
    }

    println!("{}", ans + 1);
}
