//#pragma GCC optimize ("-O3","unroll-loops") #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define REP(i, n) for(int i = 0;i < n;i++) #define REPR(i, n) for(int i = n;i >= 0;i--) #define FOR(i, m, n) for(int i = m;i < n;i++) #define FORR(i, m, n) for(int i = m;i >= n;i--) #define SORT(v, n) sort(v, v+n); #define VSORT(v) sort(v.begin(), v.end()); #define REVERSE(v,n) reverse(v,v+n); #define VREVERSE(v) reverse(v.begin(), v.end()); #define ll long long #define pb(a) push_back(a) #define m0(x) memset(x,0,sizeof(x)) #define print(x) cout< inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; } template inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; } const int MOD = 1e9 + 7; const ll INF = 1e17; const double pi = acos(-1); const double EPS = 1e-10; typedef pairP; const int MAX = 200020; template< unsigned mod > struct RollingHash { vector< unsigned > hashed, power; inline unsigned mul(unsigned a, unsigned b) const { unsigned long long x = (unsigned long long) a * b; unsigned xh = (unsigned)(x >> 32), xl = (unsigned)x, d, m; asm("divl %4; \n\t" : "=a" (d), "=d" (m) : "d" (xh), "a" (xl), "r" (mod)); return m; } RollingHash(const string &s, unsigned base = 10007) { int sz = (int)s.size(); hashed.assign(sz + 1, 0); power.assign(sz + 1, 0); power[0] = 1; for (int i = 0; i < sz; i++) { power[i + 1] = mul(power[i], base); hashed[i + 1] = mul(hashed[i], base) + s[i]; if (hashed[i + 1] >= mod) hashed[i + 1] -= mod; } } unsigned get(int l, int r) const { unsigned ret = hashed[r] + mod - mul(hashed[l], power[r - l]); if (ret >= mod) ret -= mod; return ret; } unsigned connect(unsigned h1, int h2, int h2len) const { unsigned ret = mul(h1, power[h2len]) + h2; if (ret >= mod) ret -= mod; return ret; } int LCP(const RollingHash< mod > &b, int l1, int r1, int l2, int r2) { int len = min(r1 - l1, r2 - l2); int low = -1, high = len + 1; while (high - low > 1) { int mid = (low + high) / 2; if (get(l1, l1 + mid) == b.get(l2, l2 + mid)) low = mid; else high = mid; } return (low); } }; using RH = RollingHash< 1000000007 >; int H[10100], dp[10010]; string S; int N; int func(int i,RH rh) { if (dp[i] != -1) { return dp[i]; } int res = 1; FOR(k, 1, N / 2 + 1-i) { int h1 = rh.get(i, i + k), h2 = rh.get(N - i -k, N - i); //pe(i)pe(k)pe(h1)print(h2); if (h1 == h2) { res += func(i + k, rh); res %= MOD; } } dp[i] = res; return res; } signed main() { cin.tie(0); ios::sync_with_stdio(false); string S; cin >> S; N = S.size(); RH rh(S); REP(i, 10010)dp[i] = -1; print(func(0, rh)); }