#include <bits/stdc++.h>   using namespace std;   const int maxn = 410, MOD = 10007;   char s[maxn];   int n, m, mat_s;   typedef long long Mat[maxn][maxn];   void print(Mat A) {     for (int i = 0; i < (mat_s); i++) {       for (int j = 0; j < (mat_s); j++) {         cout << A[i][j] <<    ;       }       cout << endl;     }     cout << endl;   }   void mat_mul(Mat A, Mat B, Mat res) {     static Mat C;     memset(C, 0, sizeof(C));     for (int i = 0; i < (mat_s); i++)       for (int k = (i); k <= (mat_s - 1); k++)         for (int j = (k); j <= (mat_s - 1); j++) {           C[i][j] += A[i][k] * B[k][j];         }     for (int i = 0; i < (mat_s); i++)       for (int j = 0; j < (mat_s); j++) {         C[i][j] %= MOD;       }     memcpy(res, C, sizeof(C));   }   void mat_pow(Mat A, long long k, Mat res) {     static Mat a, r;     memcpy(a, A, sizeof(a));     memset(r, 0, sizeof(r));     for (int i = 0; i < (mat_s); i++) r[i][i] = 1;     while (k) {       if (k & 1) {         mat_mul(r, a, r);       }       if (!(k >>= 1)) {         break;       }       mat_mul(a, a, a);     }     memcpy(res, r, sizeof(r));   }   int dp[210][210][210];   int rec(int l, int r, int n24) {     int& res = dp[l][r][n24];     if (~res) {       return res;     }     if (l == r) {       return res = !n24;     }     if (s[l] == s[r]) {       if (l + 1 == r) {         return res = !n24;       }       return res = rec(l + 1, r - 1, n24);     } else {       if (n24 > 0) {         return res = (rec(l + 1, r, n24 - 1) + rec(l, r - 1, n24 - 1)) % MOD;       } else {         return res = 0;       }     }   }   int n24, n25, n26, times;   int mat_at(Mat A, int c24, int c25) {     int i24 = n24 - c24;     int i25 = n24 + c25 - 1;     int i26 = i25 + n25;     return A[i24][i26];   }   int main() {     scanf( %s%d , s, &n);     m = strlen(s);     n += m;     times = (n + 1) >> 1;     n24 = m - 1;     n26 = n25 = (m + 1) >> 1;     mat_s = n24 + n25 + n26;     static Mat A, B;     for (int i = 0; i < (mat_s); i++) {       if (i < n24) {         A[i][i] = 24;         A[i][i + 1] = 1;       } else if (i < n24 + n25) {         A[i][i] = 25;         if (i + 1 < n24 + n25) {           A[i][i + 1] = 1;         }         A[i][i + n25] = 1;       } else {         A[i][i] = 26;       }     }     mat_pow(A, times - 1, B);     mat_mul(B, A, A);     int ans = 0;     memset(dp, -1, sizeof(dp));     for (int c24 = 0; c24 < (m); c24++) {       int c25 = (m - c24 + 1) >> 1;       if (times - c24 - c25 < 0) {         continue;       }       int ways = rec(0, m - 1, c24);       ans = (ans + ways * mat_at(A, c24, c25)) % MOD;       if ((n & 1) && (!((m - c24) & 1))) {         ans = (ans + MOD - ways * B[n24 - c24][n24 + c25 - 1] % MOD) % MOD;       }     }     printf( %d n , ans);     return 0;   }   