#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
const int M = 998244353;

int main(void) {
	ios::sync_with_stdio(false);
	cin.tie(nullptr), cout.tie(nullptr);
	string st;
	int d;
	cin >> st >> d;
	int n = st.length();
	map<char, int> id;
	for (auto c : st) {
		id[c] = 0;
	}
	vector<int> cnt(min(26, (int)id.size() + 1));
	int idc = 0;
	if ((int)id.size() < 26) {
		cnt[idc++] = 26 - id.size();
	}
	for (auto &[c, i] : id) {
		i = idc;
		cnt[idc++] = 1;
	}
	vector<int> f(n + 1), s(n + 1);
	for (int i = 0; i < n; i++) {
		s[i + 1] = id[st[i]];
	}
	for (int i = 0; i <= n; i++) {
		f[i] = i;
	}
	auto trans = [&](vector<int> f, int x) {
		for (int i = n; i >= 0; i--) {
			int val = f[i] + 1;
			if (i > 0) {
				val = min(val, f[i - 1] + (s[i] == x ? 0 : 1));
			}
			f[i] = min(val, d + 1);
		}
		for (int i = 1; i <= n; i++) {
			f[i] = min({f[i], f[i - 1] + 1, d + 1});
		}
		return f;
	};
	map<vector<int>, int> idx;
	vector<vector<int>> vec;
	auto getid = [&](const vector<int> &f) {
		int &res = idx[f];
		if (res == 0) {
			res = vec.size();
			vec.emplace_back(f);
		}
		return res;
	};
	auto getmin = [&](const vector<int> &f) {
		int x = d + 1;
		for (auto v : f) {
			x = min(x, v);
		}
		return x;
	};
	vector<int> g(1);
	g[getid(f)] = 1;
	int ans = (f[n] == d) ? 1 : 0;
	for (int i = 0; i < n + d; i++) {
		vector<int> ng(vec.size());
		for (int j = 0; j < (int)g.size(); j++) {
			if (g[j]) {
				for (int x = 0; x < idc; x++) {
					auto nf = trans(vec[j], x);
					if (getmin(nf) > d) {
						continue;
					}
					int k = getid(nf);
					if (k == (int)ng.size()) {
						ng.emplace_back(0);
					}
					ng[k] = (ng[k] + 1ll * g[j] * cnt[x]) % M;
				}
			}
		}
		swap(ng, g);
		for (int i = 0; i < (int)vec.size(); i++) {
			if (vec[i][n] == d) {
				ans = (ans + g[i]) % M;
			}
		}
	}
	cout << ans << '\n';
	return 0;
}