#include #include using namespace std; using namespace atcoder; #define overload4(_1, _2, _3, _4, name, ...) name #define rep1(n) for(int i = 0; i < (int)(n); ++i) #define rep2(i, n) for(int i = 0; i < (int)(n); ++i) #define rep3(i, a, b) for(int i = (a); i < (int)(b); ++i) #define rep4(i, a, b, c) for(int i = (a); i < (int)(b); i += (c)) #define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__) #define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; --i) #define ALL(a) a.begin(), a.end() #define Sort(a) sort(a.begin(), a.end()) #define RSort(a) sort(a.rbegin(), a.rend()) typedef long long int ll; typedef unsigned long long ul; typedef long double ld; typedef vector vi; typedef vector vll; typedef vector vc; typedef vector vst; typedef vector vd; typedef vector vld; typedef pair P; template long long sum(const T& a){ return accumulate(a.begin(), a.end(), 0LL); } template auto min(const T& a){ return *min_element(a.begin(), a.end()); } template auto max(const T& a){ return *max_element(a.begin(), a.end()); } const long long MINF = 0x7fffffffffff; const long long INF = 0x1fffffffffffffff; const long long MOD = 998244353; const long double EPS = 1e-9; const long double PI = acos(-1); template inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } template istream &operator>>(istream &is, pair &p){ is >> p.first >> p.second; return is; } template ostream &operator<<(ostream &os, const pair &p){ os << "(" << p.first << ", " << p.second << ")"; return os; } template istream &operator>>(istream &is, vector &v){ for(T &in : v) is >> in; return is; } template ostream &operator<<(ostream &os, const vector &v){ for(int i = 0; i < (int) v.size(); ++i){ os << v[i] << (i + 1 != (int) v.size() ? " " : ""); } return os; } template ostream &operator<<(ostream &os, const map &mp){ for(auto &[key, val] : mp){ os << key << ":" << val << " "; } return os; } template ostream &operator<<(ostream &os, const set &st){ auto itr = st.begin(); for(int i = 0; i < (int)st.size(); ++i){ os << *itr << (i + 1 != (int)st.size() ? " " : ""); itr++; } return os; } template ostream &operator<<(ostream &os, const multiset &st){ auto itr = st.begin(); for(int i = 0; i < (int)st.size(); ++i){ os << *itr << (i + 1 != (int)st.size() ? " " : ""); itr++; } return os; } template ostream &operator<<(ostream &os, queue q){ while(q.size()){ os << q.front() << " "; q.pop(); } return os; } template ostream &operator<<(ostream &os, deque q){ while(q.size()){ os << q.front() << " "; q.pop_front(); } return os; } template ostream &operator<<(ostream &os, stack st){ while(st.size()){ os << st.top() << " "; st.pop(); } return os; } template ostream &operator<<(ostream &os, priority_queue pq){ while(pq.size()){ os << pq.top() << " "; pq.pop(); } return os; } template inline T vin(T& vec, U n) { vec.resize(n); for(int i = 0; i < (int) n; ++i) cin >> vec[i]; return vec; } template inline void vout(T vec, string s = "\n"){ for(auto x : vec) cout << x << s; } template void in(T&... a){ (cin >> ... >> a); } void out(){ cout << '\n'; } template void out(const T& a, const Ts&... b){ cout << a; (cout << ... << (cout << ' ', b)); cout << '\n'; } template void inGraph(vector>& G, U n, U m, bool directed = false){ G.resize(n); for(int i = 0; i < m; ++i){ int a, b; cin >> a >> b; a--, b--; G[a].push_back(b); if(!directed) G[b].push_back(a); } } struct RollingHash{ vector hashed, power; static constexpr unsigned long long mod = (1uL << 61) - 1; unsigned long long mul(unsigned long long a, unsigned long long b) const { __int128_t t = (__int128_t) a * b; t = (t >> 61) + (t & mod); if(t >= mod) return t - mod; return t; } RollingHash(const string &s, unsigned base = 10007){ int siz = (int) s.size(); hashed.assign(siz + 1, 0); power.assign(siz + 1, 0); power[0] = 1; for(int i = 0; i < siz; 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 long long get(int l, int r) const { unsigned long long ret = hashed[r] + mod - mul(hashed[l], power[r - l]); if(ret >= mod) ret -= mod; return ret; } unsigned long long connect(unsigned long long h1, unsigned long long h2, int h2len) const { unsigned long long ret = mul(h1, power[h2len]) + h2; if(ret >= mod) ret -= mod; return ret; } int LCP(const RollingHash &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; } }; string s; ll dp[5001]; void input(){ in(s); } void solve(){ ll n = s.size(); string t = s; reverse(ALL(t)); s += t; RollingHash rh(s); vector check(n); rep(i, n){ check[i].push_back(i + 1); rep(j, i + 1, n){ ll len = j - i + 1; if(rh.get(i, i + len / 2) == rh.get(2 * n - j - 1, 2 * n - j - 1 + len / 2)){ check[i].push_back(j + 1); } } } ll ans = 1; dp[0] = n; rep(i, n){ for(auto x : check[i]){ chmax(dp[x], min(dp[i], x - i)); } } out(dp[n]); } int main(){ ios::sync_with_stdio(false); cin.tie(nullptr); cout << fixed << setprecision(20); input(); solve(); }