using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var s = ReadLine();
        var k = NN;
        var pos = 0;
        WriteLine(DFS(s, ref pos)[k]);
    }
    static int mod = 998_244_353;
    static int[][] mex = new int[][] {
        new int[] { 1, 2, 1 },
        new int[] { 2, 0, 0 },
        new int[] { 1, 0, 0 },
    };
    static int[][] max = new int[][] {
        new int[] { 0, 1, 2 },
        new int[] { 1, 1, 2 },
        new int[] { 2, 2, 2 },
    };
    static long[] DFS(string s, ref int pos)
    {
        var ans = new long[3];
        if (s[pos] != 'm')
        {
            if (s[pos] == '?') ans = new long[] { 1, 1, 1 };
            else ans[s[pos] - '0'] = 1;
            pos += 2;
            return ans;
        }
        var domex = s[pos + 1] != 'a';
        var domax = s[pos + 1] != 'e';
        long[] a;
        long[] b;
        pos += 4;
        a = DFS(s, ref pos);
        b = DFS(s, ref pos);
        ++pos;
        for (var i = 0; i < 3; ++i) for (var j = 0; j < 3; ++j)
        {
            if (domex) ans[mex[i][j]] = (ans[mex[i][j]] + a[i] * b[j] % mod) % mod;
            if (domax) ans[max[i][j]] = (ans[max[i][j]] + a[i] * b[j] % mod) % mod;
        }
        return ans;
    }
}