// 

#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;

using ll = long long;

#define rep(i, n) for (int i=0; i<(int)(n); ++(i))
#define rep3(i, m, n) for (int i=(m); (i)<(int)(n); ++(i))
#define repr(i, n) for (int i=(int)(n)-1; (i)>=0; --(i))
#define rep3r(i, m, n) for (int i=(int)(n)-1; (i)>=(int)(m); --(i))
#define all(x) (x).begin(), (x).end()

const int INF = (int)(1e9);
const ll mod = 998244353LL;

int main() {
	int n;
	string t;
	cin >> n >> t;
	int tlen = t.length();
	vector<string> s(n);
	vector<int> js(n, -1), ks(n, -1), lcnt(n);
	rep(i, n) {
		cin >> s[i];
		if (s[i] != "~") {
			lcnt[i] = s[i].length();
			continue;
		}
		cin >> js[i] >> ks[i];
		js[i]--; ks[i]--;
		if (lcnt[js[i]]+lcnt[ks[i]] <= tlen*2) {
			s[i] = s[js[i]] + s[ks[i]];
			lcnt[i] = s[i].length();
			continue;
		}
		lcnt[i] = min(INF, lcnt[js[i]]+lcnt[ks[i]]);
	}
	map<pair<int, int>, bool> bmemo, fmemo;
	unordered_map<int, ll> memo;
	auto bcheck = [&](auto bcheck, int sid, int plen) -> bool {
		if (bmemo.find({ sid, plen }) != bmemo.end()) return bmemo[{sid, plen}];
		if (plen == 0) return bmemo[{sid, plen}] = true;
		if (s[sid] != "~") {
			if (lcnt[sid] < plen) return bmemo[{sid, plen}] = false;
			return bmemo[{sid, plen}] = (s[sid].substr(lcnt[sid]-plen) == t.substr(0,plen));
		}
		else return bmemo[{sid, plen}] = bcheck(bcheck, ks[sid], plen);
	};
	auto fcheck = [&](auto fcheck, int sid, int plen) -> bool {
		if (fmemo.find({ sid, plen }) != fmemo.end()) return fmemo[{sid, plen}];
		if (plen == 0) return fmemo[{sid, plen}] = true;
		if (s[sid] != "~") {
			if (lcnt[sid] < plen) return fmemo[{sid, plen}] = false;
			return fmemo[{sid, plen}] = (s[sid].substr(0,plen) == t.substr(tlen-plen));
		}
		else return fmemo[{sid, plen}] = fcheck(fcheck, js[sid], plen);
	};
	auto calc = [&](auto calc, int sid) -> ll {
		if (memo.find(sid) != memo.end()) return memo[sid];
		ll rval = 0;
		if (lcnt[sid] < tlen) return memo[sid] = rval;
		if (s[sid] != "~") {
			for (int i=0; i+tlen-1<lcnt[sid]; ++i) if (s[sid].substr(i,tlen) == t) ++rval;
			return memo[sid] = rval;
		}
		else {
			rep3(i, 1, tlen) if (bcheck(bcheck, js[sid], tlen-i) && fcheck(fcheck, ks[sid], i)) ++rval;
			return memo[sid] = (rval + calc(calc, js[sid]) + calc(calc, ks[sid])) % mod;
		}
	};
	ll res = calc(calc, n-1);
	cout << res << endl;
	return 0;
}