#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll mod = 998244353;

vector<int> manacher(string s){
    int i = 0, j = 0;
    vector<int> res(s.size());
    while (i < s.size()) {
        while (i - j >= 0 && i + j < s.size() && s[i - j] == s[i + j]) ++j;
        res[i] = j;
        int k = 1;
        while (i - k >= 0 && i + k < s.size() && k + res[i - k] < j) res[i + k] = res[i - k], ++k;
        i += k; j -= k;
    }
    return res;
}

int main(){
    string s;
    int k;
    cin >> s >> k;
    string t = "$";
    for(int i = 0; i < k; i++){
        for(int j = 0; j < s.size(); j++){
            t += s[j];
            t += "$";
        }
    }
    vector<int> a = manacher(t);
    ll ans = 0;
    for(int i = 0; i < a.size(); i++){
        ans += a[i] / 2;
        ans %= mod;
    }
    cout << ans << endl;
}