#include <algorithm>
#include <iostream>
#include <string>
#include <vector>
using namespace std;
typedef long long ll;
int n;
string str;
int fail[1010101];
int cnt;
int grp[1010101];
vector<int> adj[1010101];
void kmp() {
int i = 1;
int j = 0;
cnt = 1;
vector<int> v;
while (i < n) {
if (str[i] == str[j]) {
grp[i] = grp[j];
for (int dif : v) {
adj[grp[i]].push_back(dif);
}
v.clear();
fail[i] = j + 1;
i++, j++;
}
else {
v.push_back(grp[j]);
if (j == 0) {
grp[i] = cnt++;
for (int dif : v) {
adj[grp[i]].push_back(dif);
adj[dif].push_back(grp[i]);
}
v.clear();
i++;
}
else {
j = fail[j - 1];
}
}
}
}
int now = 0;
bool deleted[1010101];
int delcnt = 0;
ll solve() {
for (int i = now; i < cnt; i++) {
if (adj[i].empty() || deleted[i]) continue;
now = i;
ll ans = 0;
int j = adj[i].back();
adj[i].pop_back();
if (adj[j].back() != i) remove(adj[j].begin(), adj[j].end(), i);
else adj[j].pop_back();
ans += solve();
for (int k : adj[j]) {
if (find(adj[i].begin(), adj[i].end(), k) == adj[i].end()) adj[i].push_back(k);
if (find(adj[k].begin(), adj[k].end(), i) == adj[k].end()) adj[k].push_back(i);
remove(adj[k].begin(), adj[k].end(), j);
}
adj[j].clear();
deleted[j] = true;
delcnt++;
ans -= solve();
return ans;
}
ll ans = 1;
for (int i = 0; i < cnt - delcnt; i++) {
ans *= 26;
ans %= 1000000007;
}
return ans;
}
ll order = 0;
int main() {
ios::sync_with_stdio(false);
cin.tie(NULL);
cin >> str;
n = (int)str.size();
cin >> order;
kmp();
for (int i = 0; i < cnt; i++) {
sort(adj[i].begin(), adj[i].end());
adj[i].erase(unique(adj[i].begin(), adj[i].end()), adj[i].end());
}
cout << solve() << "\n";
return 0;
}
