p5) Mr. Kitayuta's Gift

#include<iostream>
#include<string>
#include<cstdio>

using namespace std;

int main(){

    string s, aux;
    cin >> s;

    for(int i = 0; i <= s.size(); i++){

        for(char c = 'a'; c <= 'z'; c++){

            aux = s.substr(0, i);
            aux += c;
            if(i < s.size())aux += s.substr(i);

            bool pal = true;
            for(int l = 0, r = aux.size() - 1; l < r; l++, r--)if(aux[l] != aux[r])pal = false;

            if(pal){

                cout <<aux << endl;
                return 0;
            }
        }


    }
    puts("NA");
}