#include<bits/stdc++.h>
using namespace std;
using ll=long long;
template<int MOD> struct Fp{
  ll val;
  constexpr Fp(long long v = 0) noexcept : val(v % MOD) {
    if (val < 0) val += MOD;
  }
  static constexpr int getmod() { return MOD; }
  constexpr Fp operator - () const noexcept {
    return val ? MOD - val : 0;
  }
  constexpr Fp operator + (const Fp& r) const noexcept { return Fp(*this) += r; }
  constexpr Fp operator - (const Fp& r) const noexcept { return Fp(*this) -= r; }
  constexpr Fp operator * (const Fp& r) const noexcept { return Fp(*this) *= r; }
  constexpr Fp operator / (const Fp& r) const noexcept { return Fp(*this) /= r; }
  constexpr Fp& operator += (const Fp& r) noexcept {
    val += r.val;
    if (val >= MOD) val -= MOD;
    return *this;
  }
  constexpr Fp& operator -= (const Fp& r) noexcept {
    val -= r.val;
    if (val < 0) val += MOD;
    return *this;
  }
  constexpr Fp& operator *= (const Fp& r) noexcept {
    val = val * r.val % MOD;
    return *this;
  }
  constexpr Fp& operator /= (const Fp& r) noexcept {
    ll a = r.val, b = MOD, u = 1, v = 0;
    while (b) {
      ll t = a / b;
      a -= t * b, swap(a, b);
      u -= t * v, swap(u, v);
    }
    val = val * u % MOD;
    if (val < 0) val += MOD;
    return *this;
  }
  constexpr bool operator == (const Fp& r) const noexcept {
    return this->val == r.val;
  }
  constexpr bool operator != (const Fp& r) const noexcept {
    return this->val != r.val;
  }
  constexpr bool operator < (const Fp& r) const noexcept {
    return this->val < r.val;
  }
  friend constexpr istream& operator >> (istream& is, Fp<MOD>& x) noexcept {
    is >> x.val;
    x.val %= MOD;
    if (x.val < 0) x.val += MOD;
    return is;
  }
  friend constexpr ostream& operator << (ostream& os, const Fp<MOD>& x) noexcept {
    return os << x.val;
  }
  friend constexpr Fp<MOD> modpow(const Fp<MOD>& a, long long n) noexcept {
    Fp<MOD> res=1,r=a;
    while(n){
      if(n&1) res*=r;
      r*=r;
      n>>=1;
    }
    return res;
  }
  friend constexpr Fp<MOD> modinv(const Fp<MOD>& r) noexcept {
        long long a = r.val, b = MOD, u = 1, v = 0;
        while (b) {
            long long t = a / b;
            a -= t * b, swap(a, b);
            u -= t * v, swap(u, v);
        }
        return Fp<MOD>(u);
  }
  explicit operator bool()const{
		return val;
  }
};
using mint=Fp<998244353>;
int main(){
    int n;
    string S;
    cin>>n>>S;
    vector<vector<mint>> dp(n+1,vector<mint>(3));
    for(int i=1;i<=n;i++){
        if(S[i-1]=='?'){
            for(int j=0;j<3;j++){
                dp[i][j]+=dp[i-1][j]*mint(4);
                dp[i][(j+1)%3]+=dp[i-1][j]*mint(3);
                dp[i][(j+2)%3]+=dp[i-1][j]*mint(3);
            }
            dp[i][0]+=mint(4);
            dp[i][1]+=mint(3);
            dp[i][2]+=mint(3);
        }else{
            for(int j=0;j<3;j++){
                dp[i][(j+S[i-1]-'0')%3]+=dp[i-1][j];
            }
            dp[i][(S[i-1]-'0')%3]+=1;
        }
    }
    mint ans=0;
    for(int r=1;r<=n;r++){
        ans+=dp[r][0];
    }
    cout<<ans<<endl;
}