#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 3e5 + 5;
const ll base = 31;
const ll mod = 1e9 + 7;
string S;
int D_odd[N], D_even[N], n;
ll hashT[N], P10[N];
struct node{
int l, r;
ll s;
};
map<int,node> mp[N];
map<int,bool> F[N];
ll Ans = 0;
ll get(int i,int j) {
return (hashT[j] - (hashT[i - 1] * P10[j - i + 1] % mod) + mod) % mod;
}
void Cal_D_odd(){
int L = 1;
int R = 0;
for(int i = 1 ; i <= n ; ++i){
if(i > R) D_odd[i] = 0;
else D_odd[i] = min(R - i,D_odd[R - i + L]);
while(i - D_odd[i] - 1 > 0 && i + D_odd[i] + 1 <= n && S[i - D_odd[i] - 1] == S[i + D_odd[i] + 1]){
D_odd[i]++;
}
if(i + D_odd[i] > R){
R = i + D_odd[i];
L = i - D_odd[i];
}
int sz = D_odd[i] * 2 + 1;
//cout << i << "." << sz << "====\n";
if(sz > 0){
ll s = get(i - D_odd[i], i + D_odd[i]);
//cout << i - D_odd[i] << ' ' << i + D_odd[i] << ' ' << s << '\n';
int _l = i - D_odd[i];
int _r = i + D_odd[i];
if(_l <= _r && !F[sz][s]){
mp[sz][s] = {_l,_r,1};
F[sz][s] = 1;
}
else
mp[sz][s].s += 1;
}
}
}
void Cal_D_even(){
int L = 1;
int R = 0;
for(int i = 1 ; i < n ; ++i){
int j = i + 1;
if(j > R) D_even[i] = 0;
else D_even[i] = min(R - j + 1,D_even[R + L - j]);
while(i - D_even[i] > 0 && j + D_even[i] <= N && S[i - D_even[i]] == S[j + D_even[i]])
D_even[i]++;
if(i + D_even[i] > R){
R = i + D_even[i];
L = j - D_even[i];
}
int sz = D_even[i] * 2;
if(sz > 0){
ll s = get(j - D_even[i], i + D_even[i]);
//cout << D_even[i] << ' ' << j - D_even[i] << ' ' << i + D_even[i] << ' ' << s << '\n';
int _l = j - D_even[i];
int _r = i + D_even[i];
if(_l <= _r && !F[sz][s]){
mp[sz][s] = {_l,_r,1};
F[sz][s] = 1;
}
else
mp[sz][s].s += 1;
}
}
}
int main(){
cin >> S;
n = S.length();
S = ' ' + S;
P10[0] = 1;
for(int i = 1 ; i <= n ; ++i) P10[i] = P10[i - 1] * base % mod;
for(int i = 1 ; i <= n ; ++i) hashT[i] = hashT[i - 1] * base + (S[i] - 'a' + 1) % mod;
Cal_D_even();
Cal_D_odd();
for(ll i = n ; i >= 1 ; --i){
//cout << i << "====\n";
for(pair<int,node> j : mp[i]){
Ans = max(Ans, i * j.second.s);
//cout << j.second.l << ' ' << j.second.r << ' ' << j.second.s << '\n';
}
if(i - 2 >= 1)
for(pair<int,node> j : mp[i])
{
ll s = get(j.second.l + 1,j.second.r - 1);
if(!F[i - 2][s]){
mp[i - 2][s].s += mp[i][j.first].s;
mp[i - 2][s].l = j.second.l + 1;
mp[i - 2][s].r = j.second.r - 1;
F[i - 2][s] = 1;
}
else{
mp[i - 2][s].s += mp[i][j.first].s;
}
}
}
cout << Ans ;
return 0;
}
