#include <bits/stdc++.h>
#include <atcoder/modint>
using namespace std;
using namespace atcoder;
using mint = modint998244353;
#define ll long long

struct A {
    // 1-----, 1?----, 123---, ...
    vector<mint> left;

    // -----6, ----56, ---456, ...
    vector<mint> right;

    // 1?3456
    vector<mint> all;
};

vector<mint> merge(vector<mint> x, vector<mint> y) {
    int n = x.size();
    vector<mint> z(n, 0);
    for (int i=0;i<n;i++) {
        for (int j=0;j<n;j++) {
            z[(i+j)%n] += x[i]*y[j];
        }
    }
    return z;
}

vector<mint> operator+(vector<mint> lhs, vector<mint> rhs) {
    vector<mint> result = lhs;
    int n = min((int)result.size(), (int)rhs.size());
    for (int i=0;i<n;i++) result[i] += rhs[i];
    return result;
}

vector<mint> operator-(vector<mint> lhs, vector<mint> rhs) {
    vector<mint> result = lhs;
    int n = min((int)result.size(), (int)rhs.size());
    for (int i=0;i<n;i++) result[i] -= rhs[i];
    return result;
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    int N;
    string S;
    cin >> N >> S;
    
    mint ans = 0;

    vector<A> vec;
    for (int i=0;i<N;i++) {
        vector<mint> tmp_left(3, 0);
        vector<mint> tmp_right(3, 0);
        vector<mint> tmp_all(3, 0);
        if (S[i] == '?') {
            tmp_left[0] = 4;
            tmp_left[1] = 3;
            tmp_left[2] = 3;
            tmp_right[0] = 4;
            tmp_right[1] = 3;
            tmp_right[2] = 3;
            tmp_all[0] = 4;
            tmp_all[1] = 3;
            tmp_all[2] = 3;
        } else {
            tmp_left[(S[i]-'0')%3] = 1;
            tmp_right[(S[i]-'0')%3] = 1;
            tmp_all[(S[i]-'0')%3] = 1;
        }
        ans += tmp_left[0];
        vec.push_back(A{tmp_left, tmp_right, tmp_all});
    }

    while (true) {
        int n = vec.size();
        vector<A> vec_nxt;
        for (int i=0;i+1<n;i+=2) {
            vector<mint> add_vec = merge(vec[i].right, vec[i+1].left);
            ans += add_vec[0];

            vector<mint> left_nxt = vec[i].left + merge(vec[i].all, vec[i+1].left);
            vector<mint> right_nxt = vec[i+1].right + merge(vec[i+1].all, vec[i].right);
            vector<mint> all_nxt = merge(vec[i].all, vec[i+1].all);
            vec_nxt.push_back(A{left_nxt, right_nxt, all_nxt});
        }
        if (n % 2 == 1) {
            vec_nxt.push_back(vec[n-1]);
        }

        vec = vec_nxt;
        if (n == 1) break;
    }

    cout << ans.val() << "\n";
    return 0;
}