Problem:
Score : 800 points

Problem Statement

Given are integers N and X. For each integer k between 0 and X (inclusive), find the answer to the following question, then compute the sum of all those answers, modulo 998244353.

Let us repeat the following operation on the integer k. Operation: if the integer is currently odd, subtract 1 from it and divide it by 2; otherwise, divide it by 2 and add 2^{N-1} to it. How many operations need to be performed until k returns to its original value? (The answer is considered to be 0 if k never returns to its original value.)

Constraints

1 \leq N \leq 2\times 10^5

0 \leq X < 2^N

X is given in binary and has exactly N digits. (In case X has less than N digits, it is given with leading zeroes.)

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
X

Output

Print the sum of the answers to the questions for the integers between 0 and X (inclusive), modulo 998244353.

Sample Input 1

3
111

Sample Output 1

40

For example, for k=3, the operation changes k as follows: 1,0,4,6,7,3. Therefore the answer for k=3 is 6.

Sample Input 2

6
110101

Sample Output 2

616

Sample Input 3

30
001110011011011101010111011100

Sample Output 3

549320998

Solution in Rust (1.42.0) (judge verdict: Accepted)

macro_rules !read_value {($iter :expr ,($($t :tt ) ,*) ) =>{($(read_value !($iter ,$t ) ) ,*) } ;($iter :expr ,[$t :tt ;$len :expr ] ) =>{(0 ..$len ) .map (|_ |read_value !($iter ,$t ) ) .collect ::<Vec <_ >>() } ;($iter :expr ,{$t :tt =>$f :expr } ) =>{$f (read_value !($iter ,$t ) ) } ;($iter :expr ,chars ) =>{read_value !($iter ,String ) .chars () .collect ::<Vec <char >>() } ;($iter :expr ,usize1 ) =>{read_value !($iter ,usize ) -1 } ;($iter :expr ,$t :ty ) =>{$iter .next () .unwrap () .parse ::<$t >() .unwrap () } ;}
macro_rules !input_inner {($iter :expr ) =>{} ;($iter :expr ,) =>{} ;($iter :expr ,mut $var :ident :$t :tt $($r :tt ) *) =>{let mut $var =read_value !($iter ,$t ) ;input_inner !{$iter $($r ) *} } ;($iter :expr ,mut $var :ident $($r :tt ) *) =>{input_inner !{$iter ,mut $var :usize $($r ) *} } ;($iter :expr ,$var :ident :$t :tt $($r :tt ) *) =>{let $var =read_value !($iter ,$t ) ;input_inner !{$iter $($r ) *} } ;($iter :expr ,$var :ident $($r :tt ) *) =>{input_inner !{$iter ,$var :usize $($r ) *} } ;}
macro_rules !input {(source =$s :expr ,$($r :tt ) *) =>{let mut iter =$s .split_whitespace () ;input_inner !{iter ,$($r ) *} } ;(iter =$iter :ident ,$($r :tt ) *) =>{let s ={use std ::io ::Read ;let mut s =String ::new () ;std ::io ::stdin () .read_to_string (&mut s ) .unwrap () ;s } ;let mut $iter =s .split_whitespace () ;input_inner !{$iter ,$($r ) *} } ;($($r :tt ) *) =>{let s ={use std ::io ::Read ;let mut s =String ::new () ;std ::io ::stdin () .read_to_string (&mut s ) .unwrap () ;s } ;let mut iter =s .split_whitespace () ;input_inner !{iter ,$($r ) *} } ;}
pub trait Modulo: Copy {
    const MODULO: u32;
    #[inline]
    fn modulo(x: u32) -> u32 {
        x % Self::MODULO
    }
}
pub mod modulos {
    use super::*;
    #[derive(Clone, Copy, Debug, Default, Eq, Hash, Ord, PartialEq, PartialOrd)]
    pub struct Modulo1000000007 {}
    impl Modulo for Modulo1000000007 {
        const MODULO: u32 = 1_000_000_007;
    }
    #[derive(Clone, Copy, Debug, Default, Eq, Hash, Ord, PartialEq, PartialOrd)]
    pub struct Modulo1000000009 {}
    impl Modulo for Modulo1000000009 {
        const MODULO: u32 = 1_000_000_009;
    }
    #[derive(Clone, Copy, Debug, Default, Eq, Hash, Ord, PartialEq, PartialOrd)]
    pub struct Modulo998244353 {}
    impl Modulo for Modulo998244353 {
        const MODULO: u32 = 998_244_353;
    }
}
#[derive(Copy, Clone, Debug, Default, PartialEq, Eq, Hash)]
pub struct Modu32<M = modulos::Modulo1000000007>
where
    M: Modulo,
{
    x: u32,
    phantom: std::marker::PhantomData<M>,
}
impl<M: Modulo> Modu32<M> {
    #[inline]
    pub fn new(x: u32) -> Self {
        Self {
            x: M::modulo(x),
            phantom: std::marker::PhantomData,
        }
    }
    #[inline]
    pub fn new_unchecked(x: u32) -> Self {
        Self {
            x,
            phantom: std::marker::PhantomData,
        }
    }
    #[inline]
    pub fn one() -> Self {
        Self::new_unchecked(1)
    }
    #[inline]
    pub fn zero() -> Self {
        Self::new_unchecked(0)
    }
    #[inline]
    pub fn get_mod() -> u32 {
        M::MODULO
    }
    #[inline]
    pub fn pow(mut self, mut y: usize) -> Self {
        let mut x = Self::one();
        while y > 0 {
            if y & 1 == 1 {
                x *= self;
            }
            self *= self;
            y >>= 1;
        }
        x
    }
    #[inline]
    pub fn inv(self) -> Self {
        let mut a = self.x;
        let (mut b, mut u, mut s) = (M::MODULO, 1, 0);
        let k = a.trailing_zeros();
        a >>= k;
        for _ in 0..k {
            if u & 1 == 1 {
                u += M::MODULO;
            }
            u /= 2;
        }
        while a != b {
            if b < a {
                std::mem::swap(&mut a, &mut b);
                std::mem::swap(&mut u, &mut s);
            }
            b -= a;
            if s < u {
                s += M::MODULO;
            }
            s -= u;
            let k = b.trailing_zeros();
            b >>= k;
            for _ in 0..k {
                if s & 1 == 1 {
                    s += M::MODULO;
                }
                s /= 2;
            }
        }
        Self::new_unchecked(s)
    }
}
pub mod modu32_impl {
    use super::*;
    use std::{
        fmt,
        iter::{Product, Sum},
        num::ParseIntError,
        ops::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Neg, Sub, SubAssign},
        str::FromStr,
    };
    impl<M: Modulo> From<u32> for Modu32<M> {
        #[inline]
        fn from(x: u32) -> Self {
            Self::new(x)
        }
    }
    impl<M: Modulo> From<u64> for Modu32<M> {
        #[inline]
        fn from(x: u64) -> Self {
            Self::new_unchecked((x % M::MODULO as u64) as u32)
        }
    }
    impl<M: Modulo> Add for Modu32<M> {
        type Output = Self;
        #[inline]
        fn add(self, rhs: Self) -> Self::Output {
            let mut x = self.x + rhs.x;
            if x >= M::MODULO {
                x -= M::MODULO;
            }
            Self::new_unchecked(x)
        }
    }
    impl<M: Modulo> Sub for Modu32<M> {
        type Output = Self;
        #[inline]
        fn sub(self, rhs: Self) -> Self::Output {
            if self.x < rhs.x {
                Self::new_unchecked(self.x + M::MODULO - rhs.x)
            } else {
                Self::new_unchecked(self.x - rhs.x)
            }
        }
    }
    impl<M: Modulo> Mul for Modu32<M> {
        type Output = Self;
        #[inline]
        fn mul(self, rhs: Self) -> Self::Output {
            Self::new_unchecked((self.x as u64 * rhs.x as u64 % M::MODULO as u64) as u32)
        }
    }
    impl<M: Modulo> Div for Modu32<M> {
        type Output = Self;
        #[inline]
        fn div(self, rhs: Self) -> Self::Output {
            self * rhs.inv()
        }
    }
    impl<M: Modulo> Neg for Modu32<M> {
        type Output = Self;
        #[inline]
        fn neg(self) -> Self::Output {
            if self.x == 0 {
                Self::zero()
            } else {
                Self::new_unchecked(M::MODULO - self.x)
            }
        }
    }
    impl<M: Modulo> Sum for Modu32<M> {
        #[inline]
        fn sum<I: Iterator<Item = Self>>(iter: I) -> Self {
            iter.fold(Self::zero(), Add::add)
        }
    }
    impl<M: Modulo> Product for Modu32<M> {
        #[inline]
        fn product<I: Iterator<Item = Self>>(iter: I) -> Self {
            iter.fold(Self::one(), Mul::mul)
        }
    }
    impl<'a, M: Modulo + 'a> Sum<&'a Modu32<M>> for Modu32<M> {
        #[inline]
        fn sum<I: Iterator<Item = &'a Self>>(iter: I) -> Self {
            iter.fold(Self::zero(), Add::add)
        }
    }
    impl<'a, M: Modulo + 'a> Product<&'a Modu32<M>> for Modu32<M> {
        #[inline]
        fn product<I: Iterator<Item = &'a Self>>(iter: I) -> Self {
            iter.fold(Self::one(), Mul::mul)
        }
    }
    impl<M: Modulo> fmt::Display for Modu32<M> {
        fn fmt<'a>(&self, f: &mut fmt::Formatter<'a>) -> Result<(), fmt::Error> {
            write!(f, "{}", self.x)
        }
    }
    impl<M: Modulo> FromStr for Modu32<M> {
        type Err = ParseIntError;
        #[inline]
        fn from_str(s: &str) -> Result<Self, Self::Err> {
            s.parse::<u32>().map(Self::new_unchecked)
        }
    }
    macro_rules! modu32_ref_binop {
        ($imp :ident ,$method :ident ,$t :ty ) => {
            impl<M: Modulo> $imp<$t> for &$t {
                type Output = <$t as $imp<$t>>::Output;
                #[inline]
                fn $method(self, other: $t) -> <$t as $imp<$t>>::Output {
                    $imp::$method(*self, other)
                }
            }
            impl<M: Modulo> $imp<&$t> for $t {
                type Output = <$t as $imp<$t>>::Output;
                #[inline]
                fn $method(self, other: &$t) -> <$t as $imp<$t>>::Output {
                    $imp::$method(self, *other)
                }
            }
            impl<M: Modulo> $imp<&$t> for &$t {
                type Output = <$t as $imp<$t>>::Output;
                #[inline]
                fn $method(self, other: &$t) -> <$t as $imp<$t>>::Output {
                    $imp::$method(*self, *other)
                }
            }
        };
    }
    modu32_ref_binop!(Add, add, Modu32<M>);
    modu32_ref_binop!(Sub, sub, Modu32<M>);
    modu32_ref_binop!(Mul, mul, Modu32<M>);
    modu32_ref_binop!(Div, div, Modu32<M>);
    macro_rules! modu32_ref_unop {
        ($imp :ident ,$method :ident ,$t :ty ) => {
            impl<M: Modulo> $imp for &$t {
                type Output = <$t as $imp>::Output;
                #[inline]
                fn $method(self) -> <$t as $imp>::Output {
                    $imp::$method(*self)
                }
            }
        };
    }
    modu32_ref_unop!(Neg, neg, Modu32<M>);
    macro_rules! modu32_ref_op_assign {
        ($imp :ident ,$method :ident ,$t :ty ,$fromimp :ident ,$frommethod :ident ) => {
            impl<M: Modulo> $imp<$t> for $t {
                #[inline]
                fn $method(&mut self, rhs: $t) {
                    *self = $fromimp::$frommethod(*self, rhs);
                }
            }
            impl<M: Modulo> $imp<&$t> for $t {
                #[inline]
                fn $method(&mut self, other: &$t) {
                    $imp::$method(self, *other);
                }
            }
        };
    }
    modu32_ref_op_assign!(AddAssign, add_assign, Modu32<M>, Add, add);
    modu32_ref_op_assign!(SubAssign, sub_assign, Modu32<M>, Sub, sub);
    modu32_ref_op_assign!(MulAssign, mul_assign, Modu32<M>, Mul, mul);
    modu32_ref_op_assign!(DivAssign, div_assign, Modu32<M>, Div, div);
}
fn main() {
    #[allow(unused_imports)]
    use std::io::Write as _;
    let __out = std::io::stdout();
    #[allow(unused_mut, unused_variables)]
    let mut __out = std::io::BufWriter::new(__out.lock());
    #[allow(unused_macros)]
    macro_rules !print {($($arg :tt ) *) =>(::std ::write !(__out ,$($arg ) *) .unwrap () ) }
    #[allow(unused_macros)]
    macro_rules !println {($($arg :tt ) *) =>(::std ::writeln !(__out ,$($arg ) *) .unwrap () ) }
    #[allow(unused_macros)]
    macro_rules! echo {
        ($iter :expr ) => {
            echo!($iter, "\n")
        };
        ($iter :expr ,$sep :expr ) => {
            let mut iter = $iter;
            if let Some(item) = iter.next() {
                print!("{}", item);
            }
            for item in iter {
                print!("{}{}", $sep, item);
            }
            println!();
        };
    }
    input!(n, x: chars);
    let x: Vec<_> = x
        .into_iter()
        .map(|c| (c as u8 - '0' as u8) as usize)
        .collect();
    type M = Modu32<modulos::Modulo998244353>;
    let mut dp = vec![M::zero(); n + 1];
    let mut ans = M::zero();
    for i in 1..n + 1 {
        if n % i == 0 && n / i % 2 == 1 {
            let mut a = M::zero();
            for &d in &x[..i] {
                a *= M::new_unchecked(2);
                a += M::new(d as u32);
            }
            let mut ok = true;
            for j in i..n {
                let k = j % (i * 2);
                let d = if k < i { x[k] } else { 1 - x[k - i] };
                if d < x[j] {
                    break;
                }
                if d > x[j] {
                    ok = false;
                    break;
                }
            }
            if ok {
                a += M::one();
            }
            dp[i] += a;
            let mut j = i * 2;
            let d = dp[i];
            while j <= n {
                dp[j] -= d;
                j += i;
            }
            ans += dp[i] * M::new(i as u32 * 2);
        }
    }
    println!("{}", ans);
}