#include #define LLI long long int #define FOR(v, a, b) for(LLI v = (a); v < (b); ++v) #define FORE(v, a, b) for(LLI v = (a); v <= (b); ++v) #define REP(v, n) FOR(v, 0, n) #define REPE(v, n) FORE(v, 0, n) #define REV(v, a, b) for(LLI v = (a); v >= (b); --v) #define ALL(x) (x).begin(), (x).end() #define RALL(x) (x).rbegin(), (x).rend() #define ITR(it, c) for(auto it = (c).begin(); it != (c).end(); ++it) #define RITR(it, c) for(auto it = (c).rbegin(); it != (c).rend(); ++it) #define EXIST(c,x) ((c).find(x) != (c).end()) #define fst first #define snd second #define popcount __builtin_popcount #define UNIQ(v) (v).erase(unique(ALL(v)), (v).end()) #define bit(i) (1LL<<(i)) #ifdef DEBUG #include #else #define dump(...) ((void)0) #endif #define gcd __gcd using namespace std; template constexpr T lcm(T m, T n){return m/gcd(m,n)*n;} template void join(ostream &ost, I s, I t, string d=" "){for(auto i=s; i!=t; ++i){if(i!=s)ost< istream& operator>>(istream &is, vector &v){for(auto &a : v) is >> a; return is;} template bool chmin(T &a, const U &b){return (a>b ? a=b, true : false);} template bool chmax(T &a, const U &b){return (a void fill_array(T (&a)[N], const U &v){fill((U*)a, (U*)(a+N), v);} const LLI mod = 1e9+7; template class RollingHash{ private: static vector pow; public: static void init(int N){ pow.assign(N+1,0); pow[0] = 1; FORE(i,1,N){ pow[i] = pow[i-1]*BASE % MOD; } } static vector generate_hash(const T &s){ vector ret(s.size()+1); FORE(i,1,(int)s.size()){ ret[i] = (ret[i-1]*BASE+s[i-1]) % MOD; } return ret; } static LLI hash(const vector &shash, int i, int j){ // [i, j) return (shash[j] - shash[i] * pow[j-i] + MOD*MOD) % MOD; } static LLI hash(const T &p){ LLI phash = 0; REP(i,(int)p.size()) phash = (phash*BASE+p[i]) % MOD; return phash; } /* static vector find(const vector &shash, const T &p){ vector ret; int pl = p.size(); LLI phash = hash(p); REPE(i,sh-pl) if(hash(i,i+pl) == phash) ret.push_back(i); return ret; }*/ }; template vector RollingHash::pow; using RH = RollingHash; int main(){ cin.tie(0); ios::sync_with_stdio(false); RH::init(100000); string s; while(cin >> s){ int n = s.size(); int m = (n+1)/2; vector dp(m+1); auto hs = RH::generate_hash(s); if(n%2==1){ REP(i,m){ dp[i+1] = 1; REP(j,i){ if(RH::hash(hs,m+j,m+i) == RH::hash(hs,m-1-i,m-1-j)){ (dp[i+1] += dp[j+1]) %= mod; } } } }else{ dp[0] = 1; REP(i,m){ dp[i+1] = 1; REPE(j,i){ if(RH::hash(hs,m+j,m+1+i) == RH::hash(hs,m-1-i,m-j)){ (dp[i+1] += dp[j]) %= mod; } } } //join(cerr, ALL(dp)); } cout << dp[m] << endl; } return 0; }