#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
const int INF = (int) 1e9 + 1e6 + 123;
const ll LINF = (ll) 1e18 + 1e9 + 123;
const ld EPS = (ld) 1e-7;
const ll MOD = (ll) 1e9 + 7;
#define sz(x) (int) (x).size()
#define mp(x, y) make_pair(x, y)
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define lb(s, t, x) (int) (lower_bound(s, t, x) - s)
#define ub(s, t, x) (int) (upper_bound(s, t, x) - s)
#define rep(i, f, t) for (int i = f; i < t; i++)
#define per(i, f, t) for (int i = f; i >= t; i--)
ll power(ll x, ll y, ll mod = MOD) {
if (y == 0) {
return 1;
}
if (y & 1) {
return power(x, y - 1, mod) * x % mod;
} else {
ll tmp = power(x, y / 2, mod);
return tmp * tmp % mod;
}
}
template<typename A, typename B> bool mini(A &x, const B &y) {
if (y < x) {
x = y;
return true;
}
return false;
}
template<typename A, typename B> bool maxi(A &x, const B &y) {
if (y > x) {
x = y;
return true;
}
return false;
}
void add(ll &x, ll y) {
x += y;
if (x >= MOD) x -= MOD;
if (x < 0) x += MOD;
}
ll mult(ll x, ll y) {
return x * y % MOD;
}
void run();
#define TASK ""
int main() {
#ifdef LOCAL
if (strlen(TASK) > 0) {
cerr << "Reminder: you are using file i/o, filename: " TASK "!" << endl << endl;
}
#endif
#ifndef LOCAL
if (strlen(TASK)) {
freopen(TASK ".in", "r", stdin);
freopen(TASK ".out", "w", stdout);
}
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
#endif
cout << fixed << setprecision(12);
run();
return 0;
}
// == SOLUTION == //
vector<int> manaher(const string &s) {
string t;
for (char c : s) {
t += '$';
t += c;
}
t += '$';
int n = sz(t);
vector<int> res(n);
int l = -1, r = -1;
rep(i, 0, n) {
int k = 1;
if (i <= r) {
k = min(r - i + 1, res[l + r - i]);
}
while (i - k >= 0 && i + k < n && t[i - k] == t[i + k]) {
k++;
}
if (i + k - 1 > r) {
l = i - k + 1;
r = i + k - 1;
}
res[i] = k;
}
/*rep(i, 0, n) {
int k = 1;
while (i - k >= 0 && i + k < n && t[i - k] == t[i + k]) {
k++;
}
res[i] = k;
}*/
return res;
}
vector<int> suff_arr(string s) {
s += '$';
int n = sz(s);
vector<int> cl(n);
rep(i, 0, n) {
cl[i] = s[i];
}
vector<pair<pair<int, int>, int>> ids(n);
vector<int> tmp(n);
int A = max(n, 256);
vector<int> cnt(A);
for (int len = 1; len < n; len *= 2) {
fill(all(cnt), 0);
rep(i, 0, n) {
int c = cl[(i + len) % n];
cnt[c + 1]++;
}
rep(i, 1, A) {
cnt[i] += cnt[i - 1];
}
rep(i, 0, n) {
int c = cl[(i + len) % n];
tmp[cnt[c]++] = i;
}
fill(all(cnt), 0);
rep(i, 0, n) {
int id = tmp[i];
cnt[cl[id] + 1]++;
}
rep(i, 1, A) {
cnt[i] += cnt[i - 1];
}
rep(i, 0, n) {
int id = tmp[i];
ids[cnt[cl[id]]++] = {{cl[id], cl[(id + len) % n]}, id};
}
int ptr = 0;
rep(i, 0, n) {
int j = i;
cl[ids[i].second] = ptr;
while (j + 1 < n && ids[j + 1].first == ids[j].first) cl[ids[++j].second] = ptr;
ptr++;
i = j;
}
}
vector<int> res(n - 1);
rep(i, 0, n - 1) {
int pos = cl[i] - 1;
assert(pos >= 0);
res[pos] = i;
}
return res;
/*int n = sz(s);
vector<pair<string, int>> q(n);
rep(i, 0, n) q[i] = {s.substr(i), i};
sort(all(q));
vector<int> res(n);
rep(i, 0, n) res[i] = q[i].second;
return res;*/
}
vector<int> get_lcp(const string &s, const vector<int> &arr) {
int n = sz(s);
assert(sz(s) == sz(arr));
vector<int> res(n), pos(n);
rep(i, 0, n) {
pos[arr[i]] = i;
}
int k = 0;
rep(i, 0, n) {
if (k > 0) {
k--;
}
int p = pos[i];
if (p == n - 1) {
k = 0;
} else {
int j = arr[p + 1];
while (i + k < n && j + k < n && s[i + k] == s[j + k]) {
k++;
}
}
res[p] = k;
}
return res;
/*int n = sz(s);
vector<int> res(n);
rep(i, 0, n - 1) {
int k = 0;
int p = arr[i];
int q = arr[i + 1];
while (p + k < n && q + k < n && s[p + k] == s[q + k]) k++;
res[i] = k;
}
return res;*/
}
const int N = (int) 3e5 + 123;
int p[N], cnt[N], rnk[N];
void init() {
rep(i, 0, N) {
p[i] = i;
cnt[i] = 0;
rnk[i] = 0;
}
}
int get(int v) {
return (p[v] == v ? v : (p[v] = get(p[v])));
}
void unite(int u, int v) {
u = get(u);
v = get(v);
if (u == v) {
return;
}
if (rnk[u] > rnk[v]) {
swap(u, v);
} else if (rnk[u] == rnk[v]) {
rnk[v]++;
}
p[u] = v;
cnt[v] += cnt[u];
}
void run() {
string s;
cin >> s;
int n = sz(s);
vector<int> pal = manaher(s);
vector<int> arr = suff_arr(s);
vector<int> lcp = get_lcp(s, arr);
vector<int> pos(n);
rep(i, 0, n) {
pos[arr[i]] = i;
}
ll ans = 0;
vector<pair<int, int>> by_lcp(n);
rep(i, 0, n) {
by_lcp[i] = {lcp[i], i};
}
sort(all(by_lcp));
reverse(all(by_lcp));
init();
{
vector<pair<int, int>> pals(n);
rep(i, 0, n) {
pals[i] = {pal[2 * i + 1] / 2, i};
}
sort(all(pals));
reverse(all(pals));
int ptr = 0;
rep(i, 0, n) {
int len = pals[i].first;
while (ptr < n && by_lcp[ptr].first >= len) {
unite(by_lcp[ptr].second, by_lcp[ptr].second + 1);
ptr++;
}
int v = get(pos[pals[i].second]);
cnt[v]++;
maxi(ans, cnt[v] * (2LL * len - 1));
}
}
init();
{
vector<pair<int, int>> pals(n - 1);
rep(i, 1, n) {
pals[i - 1] = {pal[2 * i] / 2, i};
}
sort(all(pals));
reverse(all(pals));
int ptr = 0;
rep(i, 0, n - 1) {
int len = pals[i].first;
if (len == 0) {
break;
}
while (ptr < n && by_lcp[ptr].first >= len) {
unite(by_lcp[ptr].second, by_lcp[ptr].second + 1);
ptr++;
}
int v = get(pos[pals[i].second]);
cnt[v]++;
maxi(ans, cnt[v] * 2LL * len);
}
}
cout << ans << "\n";
}
