#include using namespace std; #define rep(i, n) for(int i = 0; i < n; i++) #define rep2(i, x, n) for(int i = x; i <= n; i++) #define rep3(i, x, n) for(int i = x; i >= n; i--) #define elif else if #define sp(x) fixed << setprecision(x) #define pb push_back #define eb emplace_back #define all(x) x.begin(), x.end() #define sz(x) (int)x.size() using ll = long long; using ld = long double; using pii = pair; using pil = pair; using pli = pair; using pll = pair; const ll MOD = 1e9+7; //const ll MOD = 998244353; const int inf = (1<<30)-1; const ll INF = (1LL<<60)-1; const ld EPS = 1e-10; template bool chmax(T &x, const T &y) {return (x < y)? (x = y, true) : false;}; template bool chmin(T &x, const T &y) {return (x > y)? (x = y, true) : false;}; template struct Mod_Int{ ll x; Mod_Int() {} Mod_Int(ll y) : x (y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {} Mod_Int &operator += (const Mod_Int &p){ x = (x + p.x) % mod; return *this; } Mod_Int &operator -= (const Mod_Int &p){ x = (x + mod - p.x) % mod; return *this; } Mod_Int &operator *= (const Mod_Int &p){ x = (x * p.x) % mod; return *this; } Mod_Int &operator /= (const Mod_Int &p){ *this *= p.inverse(); return *this; } Mod_Int &operator ++ () {return *this += Mod_Int(1);} Mod_Int operator ++ (int){ Mod_Int tmp = *this; ++*this; return tmp; } Mod_Int &operator -- () {return *this -= Mod_Int(1);} Mod_Int operator -- (int){ Mod_Int tmp = *this; --*this; return tmp; } Mod_Int operator - () const {return Mod_Int(-x);} Mod_Int operator + (const Mod_Int &p) const {return Mod_Int(*this) += p;} Mod_Int operator - (const Mod_Int &p) const {return Mod_Int(*this) -= p;} Mod_Int operator * (const Mod_Int &p) const {return Mod_Int(*this) *= p;} Mod_Int operator / (const Mod_Int &p) const {return Mod_Int(*this) /= p;} bool operator == (const Mod_Int &p) const {return x == p.x;} bool operator != (const Mod_Int &p) const {return x != p.x;} Mod_Int pow (ll n) const{ Mod_Int now = *this, ret = 1; while(n > 0){ if(n & 1) ret *= now; now *= now, n >>= 1; } return ret; } Mod_Int inverse () const{ return pow(mod-2); } friend ostream &operator << (ostream &os, const Mod_Int &p){ return os << p.x; } friend istream &operator >> (istream &is, Mod_Int &p){ ll a; is >> a; p = Mod_Int(a); return is; } }; using mint = Mod_Int; const int MAX_N = 1e6; mint fac[MAX_N+1], ifac[MAX_N+1]; void init(){ fac[0] = 1; rep2(i, 1, MAX_N){ fac[i] = fac[i-1]*i; } ifac[MAX_N] = fac[MAX_N].inverse(); rep3(i, MAX_N, 1){ ifac[i-1] = ifac[i]*i; } } mint comb(int n, int k){ return fac[n]*ifac[n-k]*ifac[k]; } mint perm(int n, int k){ return fac[n]*ifac[n-k]; } using ull = unsigned long long; template struct Rolling_Hash{ ull mod = (1UL<<61)-1; vector hashed, pw; ull mul(ull a, ull b) const{ ull a1 = a>>31, a2 = a&((1UL<<31)-1); ull b1 = b>>31, b2 = b&((1UL<<31)-1); ull ret = 2*a1*b1+a2*b2, c = a1*b2+a2*b1; ull c1 = c>>30, c2 = c&((1UL<<30)-1); ret += c1 + (c2<<31); ret = (ret>>61) + ret&mod; if(ret >= mod) ret -= mod; return ret; } Rolling_Hash(const string &s){ int n = sz(s); hashed.assign(n+1, 0); pw.assign(n+1, 0); pw[0] = 1; rep(i, n){ pw[i+1] = mul(pw[i], base); hashed[i+1] = mul(hashed[i], base)+s[i]; if(hashed[i+1] >= mod) hashed[i+1] -= mod; } } ull get(int l, int r) const{ ull ret = hashed[r]+mod-mul(hashed[l], pw[r-l]); if(ret >= mod) ret -= mod; return ret; } }; using RH = Rolling_Hash; int main(){ string S; cin >> S; int N = sz(S); mint dp[(N+1)/2]; fill(dp, dp+((N+1)/2), 1); RH rh(S); rep3(i, (N-1)/2, 0){ rep2(j, 1, (N-1)/2-i){ if(rh.get(i, i+j) == rh.get(N-i-j, N-i)) dp[i] += dp[i+j]; } } cout << dp[0] << endl; }