fn main() { let mut io = IO::new(); input! { from io, n: usize, s: [Chars; n] } const MOD: i64 = 998_244_353; let mut memo: Vec>> = vec![vec![None; n*16 + 1]; 8]; for bit in 0..8 { memo[bit][0] = Some(1); } memo[0][1] = Some(2); memo[1][1] = Some(1); memo[2][1] = Some(3); memo[3][1] = Some(2); memo[4][1] = Some(2); memo[5][1] = Some(1); memo[6][1] = Some(3); memo[7][1] = Some(3); fn calc(memo: &mut [Vec>], left_is_open: bool, right_is_open: bool, start_is_odd: bool, length: usize) -> i64 { let bit = (left_is_open as usize) << 2 | (right_is_open as usize) << 1 | start_is_odd as usize; if let Some(ret) = memo[bit][length] { ret } else { let ret = match bit { 0 => calc(memo, false, false, true, length - 1) * 2 + calc(memo, true, false, true, length - 1), 1 => calc(memo, false, false, false, length - 1) * 2, 2 => calc(memo, false, true, true, length - 1) * 2 + calc(memo, true, true, true, length - 1), 3 => calc(memo, false, true, false, length - 1) * 2, 4 => calc(memo, false, false, true, length - 1) * 2 + calc(memo, true, false, true, length - 1), 5 => calc(memo, false, false, false, length - 1) * 2 + calc(memo, true, false, true, length - 2), 6 => calc(memo, false, true, true, length - 1) * 2 + calc(memo, true, true, true, length - 1), 7 => calc(memo, false, true, false, length - 1) * 2 + calc(memo, true, true, true, length - 2), _ => unreachable!() } % MOD; memo[bit][length] = Some(ret); ret } } let s: Vec = s.into_iter().flatten().collect(); let mut ans = 1; let rl = runlength(&s); let mut cnt = 0; for (i, &(c, v)) in rl.iter().enumerate() { if c == '.' { ans = ans * calc(&mut memo, i == 0, i == rl.len() - 1, cnt & 1 == 0, v) % MOD; } cnt += v; } println!("{}", ans); } pub fn runlength(l: &[T]) -> Vec<(T, usize)> where T: PartialEq + Copy, { let mut res = Vec::new(); let mut s = l.iter(); let cur = s.next(); if cur.is_none() { return res; } let mut cur = *cur.unwrap(); let mut cnt = 1; for &x in s { if x != cur { res.push((cur, cnt)); cur = x; cnt = 1; } else { cnt += 1; } } if cnt > 0 { res.push((cur, cnt)); } res } // ------------ io module start ------------ use std::io::{stdout, BufWriter, Read, StdoutLock, Write}; pub struct IO { iter: std::str::SplitAsciiWhitespace<'static>, buf: BufWriter>, } 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(&mut self) -> ::Output { ::scan(self) } pub fn scan_vec(&mut self, n: usize) -> Vec<::Output> { (0..n).map(|_| self.scan::()).collect() } pub fn print(&mut self, x: T) { ::print(self, x); } pub fn println(&mut self, x: T) { self.print(x); self.print("\n"); } pub fn iterln>(&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 $t { type Output = Self; fn scan(s: &mut IO) -> Self::Output { s.scan_str().parse().unwrap() } } )* }; } impl_scan!(i16, i32, i64, isize, u16, u32, u64, usize, String, f32, f64); impl Scan for char { type Output = char; fn scan(s: &mut IO) -> Self::Output { s.scan_str().chars().next().unwrap() } } pub enum Bytes {} impl Scan for Bytes { type Output = &'static [u8]; fn scan(s: &mut IO) -> Self::Output { s.scan_str().as_bytes() } } pub enum Chars {} impl Scan for Chars { type Output = Vec; fn scan(s: &mut IO) -> Self::Output { s.scan_str().chars().collect() } } pub enum Usize1 {} impl Scan for Usize1 { type Output = usize; fn scan(s: &mut IO) -> Self::Output { s.scan::().wrapping_sub(1) } } impl Scan for (T, U) { type Output = (T::Output, U::Output); fn scan(s: &mut IO) -> Self::Output { (T::scan(s), U::scan(s)) } } impl Scan for (T, U, V) { type Output = (T::Output, U::Output, V::Output); fn scan(s: &mut IO) -> Self::Output { (T::scan(s), U::scan(s), V::scan(s)) } } impl Scan for (T, U, V, W) { type Output = (T::Output, U::Output, V::Output, W::Output); fn scan(s: &mut IO) -> Self::Output { (T::scan(s), U::scan(s), V::scan(s), W::scan(s)) } } pub trait Print { fn print(w: &mut IO, x: Self); } macro_rules! impl_print_int { ($($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 Print for &T { fn print(w: &mut IO, x: Self) { w.print(*x); } } impl Print for (T, U) { fn print(w: &mut IO, (x, y): Self) { w.print(x); w.print(" "); w.print(y); } } impl 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 ------------