#include <bits/stdc++.h>   using namespace std;   const int mo = 10007;   char S[205];   int n, m, M, f[205][205][205], ans;   struct O {     long long a[330][330];     void clear() { memset(a, 0, sizeof a); }   } A, B, C;   O operator*(const O &A, const O &B) {     for (int i = 0; i <= M; ++i)       for (int j = i; j <= M; ++j) {         C.a[i][j] = 0;         for (int k = 0; k <= M; ++k) C.a[i][j] += A.a[i][k] * B.a[k][j];         C.a[i][j] %= mo;       }     return C;   }   void fly(int l, int r) {     if (f[l][r][m + 3]) return;     if (l > r) {       f[l][r][0] = 1;       return;     }     if (S[l] == S[r]) {       fly(l + 1, r - 1);       for (int i = 0; i <= m; ++i) f[l][r][i] = f[l + 1][r - 1][i];     } else {       fly(l, r - 1);       fly(l + 1, r);       for (int i = 1; i <= m; ++i)         f[l][r][i] = (f[l][r - 1][i - 1] + f[l + 1][r][i - 1]) % mo;     }     f[l][r][m + 3] = 1;   }   void ply(int l, int r) {     if (f[l][r][m + 3]) return;     if (l > r) {       f[l][r][0] = 1;       return;     }     if (S[l] == S[r]) {       if (l == r) return;       ply(l + 1, r - 1);       for (int i = 0; i <= m; ++i) f[l][r][i] = f[l + 1][r - 1][i];     } else {       ply(l, r - 1);       ply(l + 1, r);       for (int i = 1; i <= m; ++i)         f[l][r][i] = (f[l][r - 1][i - 1] + f[l + 1][r][i - 1]) % mo;     }     f[l][r][m + 3] = 1;   }   int main() {     scanf( %s%d , S + 1, &n);     m = strlen(S + 1);     fly(1, m);     for (int i = 1; i < m; ++i) A.a[i][i] = 24;     for (int i = 1; i < m - 1; ++i) A.a[i][i + 1] = 1;     for (int i = 1; i < m; ++i)       A.a[i][m + (m + 1) / 2 - (m - i + 1) / 2] = f[1][m][i];     A.a[0][m] = f[1][m][0];     if (m > 1) A.a[0][1] = 1;     for (int i = m; i <= m + (m + 1) / 2 - 1; ++i)       A.a[i][i] = 25, A.a[i][i + 1] = 1;     M = m + (m + 1) / 2;     A.a[M][M] = 26;     for (int i = 0; i <= M; ++i) B.a[i][i] = 1;     for (int e = (n + m + 1) / 2 + 1; e; e >>= 1) {       if (e & 1) B = B * A;       A = A * A;     }     ans = B.a[0][M];     if ((m + n) & 1) {       memset(f, 0, sizeof f);       ply(1, m);       A.clear();       for (int i = 1; i < m; ++i) A.a[i][i] = 24;       for (int i = 1; i < m - 1; ++i) A.a[i][i + 1] = 1;       for (int i = 1; i < m; ++i)         A.a[i][m + (m + 1) / 2 - (m - i + 1) / 2] = f[1][m][i];       A.a[0][m] = f[1][m][0];       if (m > 1) A.a[0][1] = 1;       for (int i = m; i <= m + (m + 1) / 2 - 1; ++i)         A.a[i][i] = 25, A.a[i][i + 1] = 1;       M = m + (m + 1) / 2;       B.clear();       for (int i = 0; i <= M; ++i) B.a[i][i] = 1;       for (int e = (n + m + 1) / 2 + 1; e; e >>= 1) {         if (e & 1) B = B * A;         A = A * A;       }       ans -= B.a[0][M];     }     printf( %d n , (ans % mo + mo) % mo);     return 0;   }   