#include <iostream>
#include <vector>
#include <map>
#include <algorithm>
#define ll long long
using namespace std;
const int SZ = 2;
const ll MD[2] = {1000000007, 420691273};
const ll P[2] = {41, 31};
int N;
ll inv[SZ][300001];
inline ll exp(ll b, ll e, const ll& m)
{
ll ret = 1;
while (e)
{
if (e & 1) ret = ret * b % m;
b = b * b % m; e >>= 1;
}
return ret;
}
inline void compInverse()
{
for (int i = 0; i < SZ; i++) {inv[i][0] = 1; inv[i][1] = exp(P[i], MD[i] - 2, MD[i]); }
for (int i = 2; i <= N; i++)
for (int j = 0; j < SZ; j++) inv[j][i] = inv[j][i - 1] * inv[j][1] % MD[j];
}
struct RHash
{
vector<ll> pref[SZ];
ll K[SZ];
void build(const string &s)
{
for (int j = 0; j < SZ; j++)
{
pref[j].assign(s.size() + 1, 0);
K[j] = 1;
}
for (int i = 1; i <= s.size(); i++)
{
for (int j = 0; j < SZ; j++)
{
pref[j][i] = (pref[j][i - 1] + K[j] * (s[i - 1] - 'a' + 1) % MD[j]) % MD[j];
K[j] = K[j] * P[j] % MD[j];
}
}
}
inline array<ll, SZ> getHash(int L, int R)
{
array<ll, SZ> ret;
for (int i = 0; i < SZ; i++)
{
ret[i] = pref[i][R] - pref[i][L - 1];
if (ret[i] < 0) ret[i] += MD[i];
ret[i] = (ret[i] * inv[i][L - 1]) % MD[i];
}
return ret;
}
};
string S, T;
RHash A, B;
ll res = 0;
int ptr = 1, cnt[350001], sz[350001];
map<array<ll, SZ>, int> mp;
vector<int> adj[350001];
void DFS(int u)
{
for (const auto &v : adj[u])
{
DFS(v); cnt[u] += cnt[v];
}
//cerr << "DFS:" << u << " " << sz[u] << " " << cnt[u] << "\n";
res = max(res, (ll)cnt[u] * sz[u]);
}
int main()
{
//freopen("A.in", "r", stdin);
ios :: sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> S; N = S.size();
compInverse();
T = S; reverse(T.begin(), T.end());
A.build(S); B.build(T);
for (int i = 0; i < N; i++)
{
int L = 1, R = min(i, N - 1 - i) + 1;
while (L < R)
{
int M = L + R >> 1;
if (A.getHash(i + 1, i + M + 1) == B.getHash(N - i, N - i + M)) {L = M + 1;}
else {R = M;}
}
//cerr << "Solving palindrome: " << i - L + 1 << " " << i << " " << i + L - 1 << "\n";
array<ll, SZ> cur; int pv = -1;
for (int j = i + L; j > i; j--)
{
cur = A.getHash(i + 1, j);
if (mp.count(cur))
{
if (pv == -1) cnt[mp[cur]]++;
else adj[mp[cur]].push_back(pv);
pv = -1; break;
}
else
{
//cerr << ptr << " represents " << i << " " << j - 1 << "\n";
//cerr << cur[0] << " " << cur[1] << "\n";
sz[ptr] = 2 * (j - i) - 1; mp[cur] = ptr++;
if (pv == -1) cnt[mp[cur]]++;
else adj[mp[cur]].push_back(pv);
pv = mp[cur];
}
}
if (pv != -1) adj[0].push_back(pv);
}
DFS(0);
for (int i = 0; i < ptr; i++) {adj[i].clear(); cnt[i] = 0; sz[i] = 0;}
mp.clear(); ptr = 1;
for (int i = 1; i < N; i++)
{
int L = 1, R = min(i, N - i) + 1;
while (L < R)
{
int M = L + R >> 1;
if (A.getHash(i + 1, i + M) == B.getHash(N - i + 1, N - i + M)) {L = M + 1;}
else {R = M;}
}
L--;
//cerr << "Solving palindrome2: " << i - L << " " << i - 1 << " " << i << " " << i + L - 1 << "\n";
if (L)
{
array<ll, SZ> cur; int pv = -1;
for (int j = i + L; j > i; j--)
{
cur = A.getHash(i + 1, j);
if (mp.count(cur))
{
if (pv == -1) cnt[mp[cur]]++;
else adj[mp[cur]].push_back(pv);
pv = -1; break;
}
else
{
sz[ptr] = 2 * (j - i); mp[cur] = ptr++;
if (pv == -1) cnt[mp[cur]]++;
else adj[mp[cur]].push_back(pv);
pv = mp[cur];
}
}
if (pv != -1) adj[0].push_back(pv);
}
}
DFS(0);
cout << res << "\n";
return 0;
}
