#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }
#define COLOR(s) ("\x1b[" s "m")

////////////////////////////////////////////////////////////////////////////////
template <unsigned M_> struct ModInt {
  static constexpr unsigned M = M_;
  unsigned x;
  constexpr ModInt() : x(0U) {}
  constexpr ModInt(unsigned x_) : x(x_ % M) {}
  constexpr ModInt(unsigned long long x_) : x(x_ % M) {}
  constexpr ModInt(int x_) : x(((x_ %= static_cast<int>(M)) < 0) ? (x_ + static_cast<int>(M)) : x_) {}
  constexpr ModInt(long long x_) : x(((x_ %= static_cast<long long>(M)) < 0) ? (x_ + static_cast<long long>(M)) : x_) {}
  ModInt &operator+=(const ModInt &a) { x = ((x += a.x) >= M) ? (x - M) : x; return *this; }
  ModInt &operator-=(const ModInt &a) { x = ((x -= a.x) >= M) ? (x + M) : x; return *this; }
  ModInt &operator*=(const ModInt &a) { x = (static_cast<unsigned long long>(x) * a.x) % M; return *this; }
  ModInt &operator/=(const ModInt &a) { return (*this *= a.inv()); }
  ModInt pow(long long e) const {
    if (e < 0) return inv().pow(-e);
    ModInt a = *this, b = 1U; for (; e; e >>= 1) { if (e & 1) b *= a; a *= a; } return b;
  }
  ModInt inv() const {
    unsigned a = M, b = x; int y = 0, z = 1;
    for (; b; ) { const unsigned q = a / b; const unsigned c = a - q * b; a = b; b = c; const int w = y - static_cast<int>(q) * z; y = z; z = w; }
    assert(a == 1U); return ModInt(y);
  }
  ModInt operator+() const { return *this; }
  ModInt operator-() const { ModInt a; a.x = x ? (M - x) : 0U; return a; }
  ModInt operator+(const ModInt &a) const { return (ModInt(*this) += a); }
  ModInt operator-(const ModInt &a) const { return (ModInt(*this) -= a); }
  ModInt operator*(const ModInt &a) const { return (ModInt(*this) *= a); }
  ModInt operator/(const ModInt &a) const { return (ModInt(*this) /= a); }
  template <class T> friend ModInt operator+(T a, const ModInt &b) { return (ModInt(a) += b); }
  template <class T> friend ModInt operator-(T a, const ModInt &b) { return (ModInt(a) -= b); }
  template <class T> friend ModInt operator*(T a, const ModInt &b) { return (ModInt(a) *= b); }
  template <class T> friend ModInt operator/(T a, const ModInt &b) { return (ModInt(a) /= b); }
  explicit operator bool() const { return x; }
  bool operator==(const ModInt &a) const { return (x == a.x); }
  bool operator!=(const ModInt &a) const { return (x != a.x); }
  friend std::ostream &operator<<(std::ostream &os, const ModInt &a) { return os << a.x; }
};
////////////////////////////////////////////////////////////////////////////////

constexpr unsigned MO = 998244353;
using Mint = ModInt<MO>;


/*
  0^a[0] 1 0^a[1] 1 ... 1 0^a[n]
  a,b -> a+b-3  (a >= 1, b >= 2)
  
  a[i] -= 3
  a,b -> a+b  (a >= -2, b >= -1)
  -3: failed (if n >= 1)
  -2: cannot merge with its left
    cannot merge with its right -1 (if n >= 2)
    merge with 0 ==> still -2
    need +1 to the right
*/

void exper() {
  constexpr int N = 7;
  set<int> dp[N + 1];
  dp[0].insert(0);
  for (int n = 0; n < N; ++n) {
    for (const int p : dp[n]) {
      for (int i = 0; i <= 4*n; ++i) {
        dp[n + 1].insert((p & ((1<<i)-1)) | (2 << i) | (p >> i << (i+4)));
      }
    }
  }
  for (int n = 0; n <= N; ++n) {
    cerr << "|dp[n]| = " << dp[n].size() << endl;
  }
  for (int n = 0; n <= N; ++n) {
    for (const int p : dp[n]) {
      vector<int> is{-1};
      for (int i = 0; i < 4*n; ++i) if (p >> i & 1) is.push_back(i);
      is.push_back(4*n);
      vector<int> as(n + 1);
      for (int j = 0; j <= n; ++j) as[j] = (is[j + 1] - is[j] - 1) - 3;
      for (int i = 0; i < 4*n; ++i) putchar("01"[p >> i & 1]);
      cout << " " << as << endl;
    }
  }
  for (int n = 0; n <= N; ++n) {
    for (int p = 0; p < 1 << (4*n); ++p) if (__builtin_popcount(p) == n) {
      vector<int> is{-1};
      for (int i = 0; i < 4*n; ++i) if (p >> i & 1) is.push_back(i);
      is.push_back(4*n);
      vector<int> as(n + 1);
      for (int j = 0; j <= n; ++j) as[j] = (is[j + 1] - is[j] - 1) - 3;
      
      const bool brt = dp[n].count(p);
      const bool grd = [&]() -> bool {
        for (auto bs = as; ; ) {
          const int bsLen = bs.size();
          if (bsLen == 1) return true;
          if (bs[0] >= -2 && *min_element(bs.begin() + 1, bs.end()) >= -1) return true;
          for (int j = bsLen; --j >= 0; ) if (bs[j] <= -3) {
            return false;
          }
          for (int j = bsLen; --j >= 0; ) if (bs[j] == -2) {
            if (j + 1 == bsLen) return false;
            if (bs[j + 1] <= 0) {
              if (j + 2 == bsLen) return false;
              // merge bs[j+1, j+2]
              bs[j + 1] += bs[j + 2];
              bs.erase(bs.begin() + (j + 2));
              goto found;
            } else {
              // merge bs[j, j+1]
              bs[j] += bs[j + 1];
              bs.erase(bs.begin() + (j + 1));
              goto found;
            }
          }
          assert(false);
         found:{}
        }
      }();
      const bool slv = [&]() -> bool {
        if (n == 0) return true;
        for (int j = 0; j <= n; ++j) if (as[j] <= -3) return false;
        int now = 0;
        int mn = 0;
        for (int j = n; j >= 1; --j) {
          now += as[j];
          if (mn - 2 >= now) return false;
          chmin(mn, now);
        }
        return true;
      }();
      
      if (!(brt == grd && brt == slv)) {
        cerr << "FAIL ";
        for (int i = 0; i < 4*n; ++i) cerr << (p >> i & 1);
        cerr << " " << as << ": " << brt << " " << grd << " " << slv << endl;
        assert(false);
      }
    }
    cerr << "PASSED n = " << n << endl;
  }
}


int N;
char S[510];

// pos, # 1, now - mn, last
Mint dp[510][130][380][2];

int main() {
  // exper();
  
  for (; ~scanf("%d", &N); ) {
    N /= 4;
    scanf("%s", S);
    
    memset(dp, 0, sizeof(dp));
    dp[4*N][0][0][1] = 1;
    for (int i = 4*N; --i >= 0; ) {
      for (int k = 0; k <= N; ++k) for (int d = 0; d <= 3*N; ++d) for (int l = 0; l < 2; ++l) {
        if (S[i] == '?' || S[i] == '0') {
          dp[i][k][d + 1][0] += dp[i + 1][k][d][l];
        }
        if (S[i] == '?' || S[i] == '1') {
          if (d >= 2 && l == 0) {
            dp[i][k + 1][max(d - 3, 0)][1] += dp[i + 1][k][d][l];
          }
        }
      }
    }
    Mint ans = 0;
    for (int d = 0; d <= 3*N; ++d) {
      ans += dp[0][N][d][0];
    }
    printf("%u\n", ans.x);
  }
  return 0;
}