#include const int MOD = 1e9 + 7; const int B = 311; int Dp(const std::string &s) { std::vector pb(s.size() + 1); for (int i = pb[0] = 1; i <= s.size(); ++i) { pb[i] = 1LL * pb[i - 1] * B % MOD; } std::vector ph(s.size() + 1); std::vector rph(s.size() + 1); for (int i = 0; i < s.size(); ++i) { ph[i + 1] = (1LL * ph[i] * B + s[i]) % MOD; rph[i + 1] = (1LL * rph[i] * B + s[s.size() - 1 - i]) % MOD; } std::vector dp(s.size() + 1); dp[0] = 1; for (int i = 1; i <= s.size(); ++i) { for (int j = 0; j < i; ++j) { std::function&, int, int)> gh = [&](const std::vector &ph, int lb, int rb) { return ((ph[rb] - 1LL * ph[lb] * pb[rb - lb]) % MOD + MOD) % MOD; }; if (gh(ph, j, i) != gh(rph, s.size() - i, s.size() - j)) continue; (dp[i] += dp[j]) %= MOD; } } return dp[s.size()]; } signed main() { std::ios::sync_with_stdio(false); std::string S; std::cin >> S; std::cout << Dp(S) << std::endl; return 0; }