#include using namespace std; using ll = long long; using PII = pair; #define FOR(i, a, n) for (ll i = (ll)a; i < (ll)n; ++i) #define REP(i, n) FOR(i, 0, n) #define ALL(x) x.begin(), x.end() template void chmin(T &a, const T &b) { a = min(a, b); } template void chmax(T &a, const T &b) { a = max(a, b); } struct FastIO {FastIO() { cin.tie(0); ios::sync_with_stdio(0); }}fastiofastio; #ifdef DEBUG_ #include "../program_contest_library/memo/dump.hpp" #else #define dump(...) #endif const ll INF = 1LL<<60; template struct modint { ll x; modint(): x(0) {} modint(ll y) : x(y>=0 ? y%MOD : y%MOD+MOD) {} static constexpr ll mod() { return MOD; } // e乗 modint pow(ll e) { ll a = 1, p = x; while(e > 0) { if(e%2 == 0) {p = (p*p) % MOD; e /= 2;} else {a = (a*p) % MOD; e--;} } return modint(a); } modint inv() const { ll a=x, b=MOD, u=1, y=1, v=0, z=0; while(a) { ll q = b/a; swap(z -= q*u, u); swap(y -= q*v, v); swap(b -= q*a, a); } return z; } // Comparators bool operator <(modint b) { return x < b.x; } bool operator >(modint b) { return x > b.x; } bool operator<=(modint b) { return x <= b.x; } bool operator>=(modint b) { return x >= b.x; } bool operator!=(modint b) { return x != b.x; } bool operator==(modint b) { return x == b.x; } // Basic Operations modint operator+(modint r) const { return modint(*this) += r; } modint operator-(modint r) const { return modint(*this) -= r; } modint operator*(modint r) const { return modint(*this) *= r; } modint operator/(modint r) const { return modint(*this) /= r; } modint &operator+=(modint r) { if((x += r.x) >= MOD) x -= MOD; return *this; } modint &operator-=(modint r) { if((x -= r.x) < 0) x += MOD; return *this; } modint &operator*=(modint r) { #if !defined(_WIN32) || defined(_WIN64) x = x * r.x % MOD; return *this; #endif unsigned long long y = x * r.x; unsigned xh = (unsigned) (y >> 32), xl = (unsigned) y, d, m; asm( "divl %4; \n\t" : "=a" (d), "=d" (m) : "d" (xh), "a" (xl), "r" (MOD) ); x = m; return *this; } modint &operator/=(modint r) { return *this *= r.inv(); } // increment, decrement modint operator++() { x++; return *this; } modint operator++(signed) { modint t = *this; x++; return t; } modint operator--() { x--; return *this; } modint operator--(signed) { modint t = *this; x--; return t; } // 平方剰余のうち一つを返す なければ-1 friend modint sqrt(modint a) { if(a == 0) return 0; ll q = MOD-1, s = 0; while((q&1)==0) q>>=1, s++; modint z=2; while(1) { if(z.pow((MOD-1)/2) == MOD-1) break; z++; } modint c = z.pow(q), r = a.pow((q+1)/2), t = a.pow(q); ll m = s; while(t.x>1) { modint tp=t; ll k=-1; FOR(i, 1, m) { tp *= tp; if(tp == 1) { k=i; break; } } if(k==-1) return -1; modint cp=c; REP(i, m-k-1) cp *= cp; c = cp*cp, t = c*t, r = cp*r, m = k; } return r.x; } template friend modint operator*(T l, modint r) { return modint(l) *= r; } template friend modint operator+(T l, modint r) { return modint(l) += r; } template friend modint operator-(T l, modint r) { return modint(l) -= r; } template friend modint operator/(T l, modint r) { return modint(l) /= r; } template friend bool operator==(T l, modint r) { return modint(l) == r; } template friend bool operator!=(T l, modint r) { return modint(l) != r; } // Input/Output friend ostream &operator<<(ostream& os, modint a) { return os << a.x; } friend istream &operator>>(istream& is, modint &a) { is >> a.x; a.x = ((a.x%MOD)+MOD)%MOD; return is; } friend string to_frac(modint v) { static map mp; if(mp.empty()) { mp[0] = mp[MOD] = {0, 1}; FOR(i, 2, 1001) FOR(j, 1, i) if(__gcd(i, j) == 1) { mp[(modint(i) / j).x] = {i, j}; } } auto itr = mp.lower_bound(v.x); if(itr != mp.begin() && v.x - prev(itr)->first < itr->first - v.x) --itr; string ret = to_string(itr->second.first + itr->second.second * ((int)v.x - itr->first)); if(itr->second.second > 1) { ret += '/'; ret += to_string(itr->second.second); } return ret; } }; using mint = modint<1000000007>; // 「SとS[i:|S|-1]の最長共通接頭辞の長さ」を記録した配列AをO(|S|)で構築する // aaabaaaab // 921034210 vector Zalgo(string s) { vector v(s.size()); v[0] = s.size(); int i = 1, j = 0; while (i < s.size()) { while (i+j < s.size() && s[j] == s[i+j]) ++j; v[i] = j; if (j == 0) { ++i; continue;} int k = 1; while (i+k < s.size() && k+v[k] < j) v[i+k] = v[k], ++k; i += k; j -= k; } return v; } int main(void) { string s; cin >> s; const ll n = s.size(); vector dp(n/2+1); dp[0] = 1; FOR(i, 1, n/2+1) { auto v = Zalgo(s.substr(i-1)); FOR(j, i, n/2+1) if(v[n-j-(i-1)] >= j-i+1) dp[j] += dp[i-1]; } mint ret = 0; REP(i, n/2+1) ret += dp[i]; cout << ret << endl; return 0; }