#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; typedef long long ll; typedef unsigned long long ull; typedef vector vec; typedef vector mat; #define rep(i, n) for(ll i = 0; i < (n); i++) #define revrep(i, n) for(ll i = (n-1); i >= 0; i--) #define pb push_back #define f first #define s second ll max(ll a, ll b){return (a > b) ? a : b;} ll min(ll a, ll b){return (a < b) ? a : b;} ll max3(ll a, ll b, ll c){return max(a, max(b, c));}; ll min3(ll a, ll b, ll c){return min(a, min(b, c));}; ll max4(ll a, ll b, ll c, ll d){return max(max(a, b), min(c, d));}; ll min4(ll a, ll b, ll c, ll d){return min(min(a, b), min(c, d));}; ll max5(ll a, ll b, ll c, ll d, ll e){return max(max(a, b), max3(c, d, e));}; ll min5(ll a, ll b, ll c, ll d, ll e){return min(min(a, b), min3(c, d, e));}; const ll INFL = 1LL << 60;//10^18 = 2^60 const int INF = 1 << 30;//10^9 ll MOD = 1000000007; //ll MOD = 998244353; vector dy = {0, 0, 1, -1, 1, 1, -1, -1, 0}; vector dx = {1, -1, 0, 0, 1, -1, 1, -1, 0}; ll pow_long(ll x, ll k){ ll res = 1; while(k > 0){ if(k % 2) res *= x; x *= x; k /= 2; } return res; } ll pow_mod(ll x, ll k){ x %= MOD; x += MOD; x %= MOD; ll res = 1; while(k > 0){ if(k % 2){ res *= x; res %= MOD; } x *= x; x %= MOD; k /= 2; } return res; } ll inverse(ll x){return pow_mod(x, MOD - 2);}; ll gcd(ll a, ll b){ if(b == 0) return a; return gcd(b, a % b); } ll lcm(ll x, ll y){return x / gcd(x, y) * y;}; ll kai_mod(ll x){ if(x == 0) return 1; return x * kai_mod(x-1) % MOD; } /* //コンビネーション const int MAXcomb = 200010; ll fac[MAXcomb], finv[MAXcomb], inv[MAXcomb]; //facはn!,finvは1/n! //invは逆元 void COMinit(){ fac[0] = fac[1] = 1; finv[0] = finv[1] = 1; inv[1] = 1; for(int i = 2; i < MAXcomb; i++){ fac[i] = fac[i-1] * i % MOD; inv[i] = MOD - inv[MOD%i] * (MOD/i) % MOD; finv[i] = finv[i-1] * inv[i] % MOD; } } ll comb(int n, int k){ if(n < k) return 0; if(n < 0 || k < 0) return 0; return fac[n] * finv[k] % MOD * finv[n-k] % MOD; } */ struct RollingHash{ string S; ll sl;//Sのサイズ vector hashed, power; ll base = 998244353; ll MOD = 1000000007; void getS(string S){ S = S; sl = S.size(); hashed.resize(sl + 1, 0); power.resize(sl + 1); power[0] = 1; rep(i, sl){ power[i+1] = (power[i] * base) % MOD; hashed[i+1] = (hashed[i] * base + S[i]) % MOD; } } ll getHash(ll l, ll r){//1-index //abcdef => (2, 4] => cd //abcdef => (0, 6] => abcdef ll res = ((hashed[r] - hashed[l] * power[r-l]) % MOD + MOD) % MOD; return res; } //使ったことない ll connect(ll hash1, ll hash2, ll hash2size){ ll res = (hash1 * power[hash2size] + hash2) % MOD; return res; } }; int main(){ string S; cin >> S; ll sl = S.size(); RollingHash SH; SH.getS(S); vector dp(sl/2+1, 0); dp[0] = 1; for(ll i = 1; i <= sl/2; i++){ for(ll j = 1; j <= i; j++){ if(SH.getHash(i-j, i) == SH.getHash(sl-i, sl-(i-j))){ dp[i] += dp[i-j]; dp[i] %= MOD; } } } ll ans = 0; rep(i, sl/2+1) ans = (ans + dp[i]) % MOD; cout << ans << endl; }