func_code_string: #include <bits/stdc++.h>   using namespace std;   using std::bitset;   const double Pi = acos(-1);   namespace fastIO {   template <class T>   inline void read(T &x) {     x = 0;     bool fu = 0;     char ch = 0;     while (ch >  9  || ch <  0 ) {       ch = getchar();       if (ch ==  - ) fu = 1;     }     while (ch <=  9  && ch >=  0 ) x = (x * 10 - 48 + ch), ch = getchar();     if (fu) x = -x;   }   inline int read() {     int x = 0;     bool fu = 0;     char ch = 0;     while (ch >  9  || ch <  0 ) {       ch = getchar();       if (ch ==  - ) fu = 1;     }     while (ch <=  9  && ch >=  0 ) x = (x * 10 - 48 + ch), ch = getchar();     return fu ? -x : x;   }   char _n_u_m_[40];   template <class T>   inline void write(T x) {     if (x == 0) {       putchar( 0 );       return;     }     T tmp = x > 0 ? x : -x;     if (x < 0) putchar( - );     register int cnt = 0;     while (tmp > 0) {       _n_u_m_[cnt++] = tmp % 10 +  0 ;       tmp /= 10;     }     while (cnt > 0) putchar(_n_u_m_[--cnt]);   }   template <class T>   inline void write(T x, char ch) {     write(x);     putchar(ch);   }   }  // namespace fastIO   using namespace fastIO;   const int MAXN = 1000005;   int len[MAXN], ch[MAXN][26], fail[MAXN], cnt, lst, up[MAXN], orz[MAXN];   long long qwq[MAXN], ans[MAXN];   char c[MAXN], ccf[MAXN];   int now, n;   inline void insert(int pos) {     while (c[pos] != c[pos - len[lst] - 1]) lst = fail[lst];     if (!ch[lst][c[pos] - 97]) {       len[++cnt] = len[lst] + 2;       register int i = fail[lst];       while (c[pos] != c[pos - len[i] - 1]) i = fail[i];       fail[cnt] = ch[i][c[pos] - 97];       ch[lst][c[pos] - 97] = cnt;       orz[cnt] = len[cnt] - len[fail[cnt]];       if (orz[cnt] == orz[fail[cnt]])         up[cnt] = up[fail[cnt]];       else         up[cnt] = fail[cnt];     }     lst = ch[lst][c[pos] - 97];   }   int main() {     len[1] = -1;     fail[0] = 1;     up[0] = 1;     ans[0] = 1;     cnt = 1;     scanf( %s , ccf + 1);     n = strlen(ccf + 1);     if (n % 2) {       cerr <<  Fuck CCF!!!  << endl;       cout << 0;       return 0;     }     for (register int i = 1, iend = n / 2; i <= iend; ++i) {       c[2 * i - 1] = ccf[i];       c[i << 1] = ccf[n - i + 1];     }     for (register int i = 1, iend = n; i <= iend; ++i) {       insert(i);       for (register int j = lst; j; j = up[j]) {         qwq[j] = ans[i - len[up[j]] - orz[j]];         if (up[j] != fail[j]) qwq[j] += qwq[fail[j]];         qwq[j] %= 1000000007ll;         if (!(i & 1)) ans[i] += qwq[j], ans[i] %= 1000000007ll;       }     }     cout << ans[n];     return 0;   }   