#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;
    ll k;
    cin >> s >> k;
    ll n = s.size();
    string t = "$";
    for(int i = 0; i < min(k, 3LL); i++){
        for(int j = 0; j < n; j++){
            t += s[j];
            t += "$";
        }
    }
    vector<int> a = manacher(t);
    ll ans = 0;
    if(k <= 3){
        for(int i = 0; i < a.size(); i++){
            ans = (ans + a[i] / 2) % mod;
        }
        cout << ans << endl;
        return 0;
    }
    ll l = (k + 1) / 2, r = k / 2;
    for(int i = 2 * n; i < 4 * n; i++){
        if(a[i] >= 2 * n){
            ll mr = min(i - 2 * n + 1, 4 * n - i + 1) / 2;
            ll Mr = max(i - 2 * n + 1, 4 * n - i + 1) / 2;
            ans = (ans + l * (l - 1) / 2 % mod * n % mod + l * mr % mod) % mod;
            ans = (ans + r * (r - 1) / 2 % mod * n % mod + r * Mr % mod) % mod;
        }else{
            ans = (ans + a[i] / 2 * (k - 2) % mod + a[i - 2 * n] / 2 + a[2 * n + i] / 2) % mod;
        }
    }
    cout << ans << endl;
}