#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef DEBUG #include "./Lib/debug.hpp" #else #define dump(...) templateinline auto d_val(T a, T b) { return a; } #endif /* (=^o^=) */ #define int ll /* macro */ #define FOR(i, b, e) for(ll i = (ll)(b); i < (ll)(e); ++i) #define RFOR(i, b, e) for(ll i = (ll)(e-1); i >= (ll)(b); --i) #define REP(i, n) FOR(i, 0, n) #define RREP(i, n) RFOR(i, 0, n) #define REPC(x,c) for(const auto& x:(c)) #define REPI2(it,b,e) for(auto it = (b); it != (e); ++it) #define REPI(it,c) REPI2(it, (c).begin(), (c).end()) #define RREPI(it,c) REPI2(it, (c).rbegin(), (c).rend()) #define REPI_ERACE2(it, b, e) for(auto it = (b); it != (e);) #define REPI_ERACE(it, c) REPI_ERACE2(it, (c).begin(), (c).end()) #define ALL(x) (x).begin(),(x).end() #define cauto const auto& /* macro func */ #define SORT(x) do{sort(ALL(x));}while(false) #define RSORT(x) do{sort((x).rbegin(),(x).rend());}while(false) #define UNIQUE(v) do{v.erase( unique(v.begin(), v.end()), v.end() );}while(false) #define MAX(x,y) do{x = std::max(x,y);}while(false) #define MIN(x,y) do{x = std::min(x,y);}while(false) #define BR do{cout<<"\n";}while(false) /* type define */ using ll = long long; using PAIR = std::pair; using VS = std::vector; using VL = std::vector; using VVL = std::vector; using VVVL = std::vector; using VD = std::vector; template using V = std::vector; /* using std */ using std::cout; constexpr char endl = '\n'; using std::cin; using std::sort; using std::pair; using std::string; using std::stack; using std::queue; using std::vector; using std::list; using std::map; using std::unordered_map; using std::multimap; using std::unordered_multimap; using std::set; using std::unordered_set; using std::unordered_multiset; using std::multiset; using std::bitset; using std::priority_queue; /* constant value */ constexpr ll MOD = 1000000007; //constexpr ll MOD = 998244353; /* Initial processing */ struct Preprocessing { Preprocessing() { std::cin.tie(0); std::ios::sync_with_stdio(0); }; }_Preprocessing; /* Remove the source of the bug */ signed pow(signed, signed) { assert(false); return -1; } /* define hash */ namespace std { template <> class hash> { public: size_t operator()(const std::pair& x) const { return hash()(1000000000 * x.first + x.second); } }; } /* input */ template std::istream& operator >> (std::istream& is, vector& vec) { for (T& x : vec) is >> x; return is; } //============================================================================================= class ZAlgorithm { const std::vector m_zArray; static auto constrcutZArray(const std::string& str) { auto sz = str.size(); auto zArray = std::vector(sz); zArray[0] = sz; int i = 1, j = 0; while (i < sz) { while (i + j < sz && str[j] == str[i + j]) ++j; zArray[i] = j; if (j == 0) { ++i; continue; } int k = 1; while (i + k < sz && k + zArray[k] < j) { zArray[i + k] = zArray[k]; ++k; } i += k; j -= k; } return zArray; } public: ZAlgorithm(const std::string& str) :m_zArray(constrcutZArray(str)) {} auto getZArray() const { return m_zArray; } /* output fot debug */ void debugOutput() const { dump(m_zArray); } }; signed main() { string str; cin >> str; auto sz = static_cast(str.size()); VL dp((sz + 1) / 2, 1); REP(i, (sz + 1) / 2) { auto s = str.substr((sz + 1) / 2 - i - 1, 2 * i + 1 + (!(sz & 1))); auto z = ZAlgorithm(s).getZArray(); auto ssz = static_cast(s.size()); REP(j, s.size() / 2) { if (z[ssz - (j + 1)] == j + 1) { auto p = sz / 2 - j - 1; if (p >= 0) { dp[i] += dp[p]; dp[i] %= MOD; } }; } } dump(dp); cout << *dp.rbegin() << endl; }