fn main() {
    let mut io = IO::new();
    input! { from io,
        n: usize,
        s: [Chars; n]
    }
    const MOD: i64 = 998_244_353;
    let s: Vec<char> = s
        .into_iter()
        .flatten()
        .chain(std::iter::once('.'))
        .collect();
    let mut prv = vec![1, 0, 0];
    let mut nxt = vec![0, 0, 0];
    for (i, (&c, &d)) in s.iter().zip(s[1..].iter()).enumerate() {
        nxt.fill(0);
        let t = prv.iter().sum::<i64>() % MOD;
        let c0 = if i & 1 == 0 { prv[0] } else { t };
        let c1 = if i & 1 == 0 { t } else { t - prv[0] };
        if c == '.' {
            nxt[0] = c0;
            match d {
                'd' => {
                    nxt[2] = c1;
                }
                'k' => {
                    nxt[1] = c1;
                }
                _ => {
                    nxt[1] = c1;
                    nxt[2] = c1;
                }
            }
        } else {
            let idx = if c == 'd' { 1 } else { 2 };
            nxt[idx] = c1;
        }
        std::mem::swap(&mut prv, &mut nxt);
    }
    io.println(prv.iter().sum::<i64>().rem_euclid(MOD));
}

// ------------ io module start ------------
use std::io::{stdout, BufWriter, Read, StdoutLock, Write};

pub struct IO {
    iter: std::str::SplitAsciiWhitespace<'static>,
    buf: BufWriter<StdoutLock<'static>>,
}

impl IO {
    pub fn new() -> Self {
        let mut input = String::new();
        std::io::stdin().read_to_string(&mut input).unwrap();
        let input = Box::leak(input.into_boxed_str());
        let out = Box::new(stdout());
        IO {
            iter: input.split_ascii_whitespace(),
            buf: BufWriter::new(Box::leak(out).lock()),
        }
    }
    fn scan_str(&mut self) -> &'static str {
        self.iter.next().unwrap()
    }
    pub fn scan<T: Scan>(&mut self) -> <T as Scan>::Output {
        <T as Scan>::scan(self)
    }
    pub fn scan_vec<T: Scan>(&mut self, n: usize) -> Vec<<T as Scan>::Output> {
        (0..n).map(|_| self.scan::<T>()).collect()
    }
    pub fn print<T: Print>(&mut self, x: T) {
        <T as Print>::print(self, x);
    }
    pub fn println<T: Print>(&mut self, x: T) {
        self.print(x);
        self.print("\n");
    }
    pub fn iterln<T: Print, I: IntoIterator<Item = T>>(&mut self, iter: I, delim: &str) {
        let mut iter = iter.into_iter();
        if let Some(v) = iter.next() {
            self.print(v);
            for v in iter {
                self.print(delim);
                self.print(v);
            }
        }
        self.print("\n");
    }
    pub fn flush(&mut self) {
        self.buf.flush().unwrap();
    }
}

impl Default for IO {
    fn default() -> Self {
        Self::new()
    }
}

pub trait Scan {
    type Output;
    fn scan(io: &mut IO) -> Self::Output;
}

macro_rules! impl_scan {
    ($($t:tt),*) => {
        $(
            impl Scan for $t {
                type Output = Self;
                fn scan(s: &mut IO) -> Self::Output {
                    s.scan_str().parse().unwrap()
                }
            }
        )*
    };
}

impl_scan!(i16, i32, i64, isize, u16, u32, u64, usize, String, f32, f64);

impl Scan for char {
    type Output = char;
    fn scan(s: &mut IO) -> Self::Output {
        s.scan_str().chars().next().unwrap()
    }
}

pub enum Bytes {}
impl Scan for Bytes {
    type Output = &'static [u8];
    fn scan(s: &mut IO) -> Self::Output {
        s.scan_str().as_bytes()
    }
}

pub enum Chars {}
impl Scan for Chars {
    type Output = Vec<char>;
    fn scan(s: &mut IO) -> Self::Output {
        s.scan_str().chars().collect()
    }
}

pub enum Usize1 {}
impl Scan for Usize1 {
    type Output = usize;
    fn scan(s: &mut IO) -> Self::Output {
        s.scan::<usize>().wrapping_sub(1)
    }
}

impl<T: Scan, U: Scan> Scan for (T, U) {
    type Output = (T::Output, U::Output);
    fn scan(s: &mut IO) -> Self::Output {
        (T::scan(s), U::scan(s))
    }
}

impl<T: Scan, U: Scan, V: Scan> Scan for (T, U, V) {
    type Output = (T::Output, U::Output, V::Output);
    fn scan(s: &mut IO) -> Self::Output {
        (T::scan(s), U::scan(s), V::scan(s))
    }
}

impl<T: Scan, U: Scan, V: Scan, W: Scan> Scan for (T, U, V, W) {
    type Output = (T::Output, U::Output, V::Output, W::Output);
    fn scan(s: &mut IO) -> Self::Output {
        (T::scan(s), U::scan(s), V::scan(s), W::scan(s))
    }
}

pub trait Print {
    fn print(w: &mut IO, x: Self);
}

macro_rules! impl_print_int {
    ($($t:ty),*) => {
        $(
            impl Print for $t {
                fn print(w: &mut IO, x: Self) {
                    w.buf.write_all(x.to_string().as_bytes()).unwrap();
                }
            }
        )*
    };
}

impl_print_int!(i16, i32, i64, isize, u16, u32, u64, usize, f32, f64);

impl Print for u8 {
    fn print(w: &mut IO, x: Self) {
        w.buf.write_all(&[x]).unwrap();
    }
}

impl Print for &[u8] {
    fn print(w: &mut IO, x: Self) {
        w.buf.write_all(x).unwrap();
    }
}

impl Print for &str {
    fn print(w: &mut IO, x: Self) {
        w.print(x.as_bytes());
    }
}

impl Print for String {
    fn print(w: &mut IO, x: Self) {
        w.print(x.as_bytes());
    }
}

impl<T: Print + Copy> Print for &T {
    fn print(w: &mut IO, x: Self) {
        w.print(*x);
    }
}

impl<T: Print, U: Print> Print for (T, U) {
    fn print(w: &mut IO, (x, y): Self) {
        w.print(x);
        w.print(" ");
        w.print(y);
    }
}

impl<T: Print, U: Print, V: Print> Print for (T, U, V) {
    fn print(w: &mut IO, (x, y, z): Self) {
        w.print(x);
        w.print(" ");
        w.print(y);
        w.print(" ");
        w.print(z);
    }
}

pub mod neboccoio_macro {
    #[macro_export]
    macro_rules! input {
        (@start $io:tt @read @rest) => {};

        (@start $io:tt @read @rest, $($rest: tt)*) => {
            input!(@start $io @read @rest $($rest)*)
        };

        (@start $io:tt @read @rest mut $($rest:tt)*) => {
            input!(@start $io @read @mut [mut] @rest $($rest)*)
        };

        (@start $io:tt @read @rest $($rest:tt)*) => {
            input!(@start $io @read @mut [] @rest $($rest)*)
        };

        (@start $io:tt @read @mut [$($mut:tt)?] @rest $var:tt: [[$kind:tt; $len2: expr]; $len1:expr] $($rest:tt)*) => {
            let $($mut)* $var = (0..$len1).map(|_| $io.scan_vec::<$kind>($len2)).collect::<<$kind as Scan>::Output>();
            input!(@start $io @read @rest $($rest)*)
        };

        (@start $io:tt @read @mut [$($mut:tt)?] @rest $var:tt: [$kind:tt; $len:expr] $($rest:tt)*) => {
            let $($mut)* $var = $io.scan_vec::<$kind>($len);
            input!(@start $io @read @rest $($rest)*)
        };

        (@start $io:tt @read @mut [$($mut:tt)?] @rest $var:tt: $kind:tt $($rest:tt)*) => {
            let $($mut)* $var = $io.scan::<$kind>();
            input!(@start $io @read @rest $($rest)*)
        };

        (from $io:tt $($rest:tt)*) => {
            input!(@start $io @read @rest $($rest)*)
        };
    }
}

// ------------ io module end ------------