func_code_string: #include <bits/stdc++.h>   using namespace std;   bool p(string s) {     int n = s.length();     for (int i = 0; i < n / 2; i++) {       if (s[i] != s[n - i - 1]) return 0;     }     return 1;   }   int main() {     std::ios::sync_with_stdio(false);     string s;     cin >> s;     int n = s.length();     for (char c =  a ; c <=  z ; c++) {       string tmp = s;       for (int i = 0; i <= n; i++) {         tmp.insert(tmp.begin() + i, c);         if (p(tmp)) {           cout << tmp << endl;           return 0;         }         tmp = s;       }     }     cout <<  NA  << endl;     return 0;   }   