// Code by Parsa Eslami
#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#define pii pair<int,int>
#define bit(i,j) ((j>>i)&1)
#define FOR(i,a,b) for(int i=a;i<=b;i++)
#define FORR(i,a,b) for(int i=a;i>=b;i--)
#define S second
#define F first
#define pb push_back
#define SZ(x) (int)x.size()
#define all(x) x.begin(),x.end()
#define err(x) cout<<#x<<": "<<x<<'\n';
using namespace std;
const int BASE=131;
const int MOD=998765431;
const int N=3e5+1e4;
struct fenwick{
int fen[2*N],S,pw[20];
fenwick(){
pw[0]=1;
FOR(i,1,19) pw[i]=pw[i-1]*2;
}
void insert(int k){
if(!k){
S++;
return;
}
while(k<2*N){
fen[k]++;
k+=(k&(-k));
}
}
int get(int k){
int rt=S;
while(k>0){
rt+=fen[k];
k-=(k&(-k));
}
return rt;
}
void clear(){
FOR(i,0,2*N-1) fen[i]=0;
S=0;
}
int BSR(int X){
int val=get(X);
int ind=0;
int sum=S;
FORR(j,19,0) if(ind+pw[j]<2*N&&sum+fen[ind+pw[j]]<=val){
sum+=fen[ind+pw[j]];
ind+=pw[j];
}
return (ind+1);
}
int BSL(int X){
int val=get(X)-1;
if(val==S-1) return 0;
int ind=0;
int sum=S;
FORR(j,19,0) if(ind+pw[j]<2*N&&sum+fen[ind+pw[j]]<=val){
sum+=fen[ind+pw[j]];
ind+=pw[j];
}
return (ind+1);
}
};fenwick fen;
string s;
int n;
int arr[2*N];
int hshR[N],hsh[N];
int PAL[2*N];
int pw[N],inv[N];
vector<int> suffix_array(string S){
S.push_back(0);
int N = S.size();
vector<int> cnt(128, 0);
for (int i = 0; i < N; i++){
cnt[S[i]]++;
}
for (int i = 0; i < 127; i++){
cnt[i + 1] += cnt[i];
}
vector<int> SA(N);
for (int i = 0; i < N; i++){
cnt[S[i]]--;
SA[cnt[S[i]]] = i;
}
vector<int> rank(N);
rank[SA[0]] = 0;
for (int i = 0; i < N - 1; i++){
rank[SA[i + 1]] = rank[SA[i]];
if (S[SA[i]] != S[SA[i + 1]]){
rank[SA[i + 1]]++;
}
}
int L = 1;
while (L < N){
vector<int> SA2(N);
for (int i = 0; i < N; i++){
SA2[i] = SA[i] - L;
if (SA2[i] < 0){
SA2[i] += N;
}
}
cnt = vector<int>(N, 0);
for (int i = 0; i < N; i++){
cnt[rank[SA2[i]]]++;
}
for (int i = 0; i < N - 1; i++){
cnt[i + 1] += cnt[i];
}
for (int i = N - 1; i >= 0; i--){
cnt[rank[SA2[i]]]--;
SA[cnt[rank[SA2[i]]]] = SA2[i];
}
vector<int> rank2(N);
rank2[SA[0]] = 0;
for (int i = 0; i < N - 1; i++){
rank2[SA[i + 1]] = rank2[SA[i]];
if (rank[SA[i]] != rank[SA[i + 1]] || rank[(SA[i] + L) % N] != rank[(SA[i + 1] + L) % N]){
rank2[SA[i + 1]]++;
}
}
rank = rank2;
L *= 2;
}
SA.erase(SA.begin());
return SA;
}
inline int mul(int a,int b){
int rt=(1LL*a*b)%MOD;
return rt;
}
inline int mkey(int a,int b){
int rt=a+b;
if(rt<0) rt+=MOD;
if(rt>=MOD) rt-=MOD;
return rt;
}
int HSH(int l,int r){
int rt=mkey(hsh[r],-hsh[l-1]);
rt=mul(rt,inv[l-1]);
return rt;
}
int HSHR(int l,int r){
int rt=mkey(hshR[l],-hshR[r+1]);
rt=mul(rt,inv[n-r]);
return rt;
}
int PW(int a,int b){
if(!b) return 1;
int rt=PW(a,b/2);
rt=mul(rt,rt);
if(b&1) rt=mul(rt,a);
return rt;
}
int lcp(int I,int J){
int l=0,r=n+1;
while(r-l>1){
int mid=(r+l)/2;
if(max(I,J)+mid>(n+1)) r=mid;
else if(HSH(I,I+mid-1)==HSH(J,J+mid-1)) l=mid;
else r=mid;
}
return l;
}
int pal(int i,int j){
int l=0,r=n+1;
while(r-l>1){
int mid=(r+l)/2;
if(i-mid<0||j+mid>(n+1)) r=mid;
else if(HSHR(i-mid+1,i)==HSH(j,j+mid-1)) l=mid;
else r=mid;
}
return l;
}
int32_t main(){
ios_base::sync_with_stdio(0); cin.tie(0);
pw[0]=1; inv[0]=1; FOR(i,1,N-1) pw[i]=mul(pw[i-1],BASE),inv[i]=PW(pw[i],MOD-2);
cin>>s; vector<int> X0=suffix_array(s); n=SZ(s);
s='$'+s;
hsh[0]=0;
FOR(i,1,n) hsh[i]=mkey(hsh[i-1],mul((s[i]-'a'+1),pw[i-1]));
hshR[n+1]=0;
FORR(i,n,1) hshR[i]=mkey(hshR[i+1],mul((s[i]-'a'+1),pw[n-i]));
int sa[n+1];
FOR(i,1,n) sa[i]=X0[i-1]+1;
int to[n+1]; FOR(i,1,n) to[sa[i]]=i;
int num[2*n]={};
FOR(i,1,n){
num[2*i-1]=pal(i,i);
if(i!=n) num[2*i]=pal(i,i+1);
}
FOR(i,1,n){
arr[2*i-1]=n+1-sa[i];
if(i!=n) arr[2*i]=lcp(sa[i],sa[i+1]);
}
FOR(i,1,n){
num[2*i-1]-=i;
if(i!=n) num[2*i]-=i;
}
vector<int> ind[2*n];
FOR(i,1,2*n-1) ind[num[i]+n].pb(i);
FOR(j,n+1,2*n-1) for(int x0:ind[j]) fen.insert(x0);
fen.insert(2*n+1);
FOR(i,1,n){
for(int x0:ind[n+1-i]) fen.insert(x0);
int mid=0;
mid=(i+n)/2;
if((i+n)%2==0){
mid=mid*2-1;
}else{
mid=mid*2;
}
int it=fen.BSL(mid);
PAL[2*to[i]-1]=(it)-(2*i-1)+1;
if(to[i]!=n&&arr[2*to[i]]){
int X=i+arr[2*to[i]]-1;
mid=(i+X)/2;
if((i+X)%2==0){
mid=mid*2-1;
}else mid=mid*2;
it=fen.BSL(mid);
PAL[2*to[i]]=(it)-(2*i-1)+1;
}
}
vector<pair<pii,int>> vc;
FOR(i,1,2*n-1){
vc.pb({{arr[i],i&1},i});
}
sort(all(vc));
fen.clear();
fen.insert(2*n);
fen.insert(0);
long long ans=0;
FOR(i,0,2*n-2){
int I=vc[i].S;
int it=fen.BSR(I);
int R=it; R--;
it=fen.BSL(I);
int L=it; L++;
ans=max(ans,1LL*((R-L+2)/2)*PAL[I]);
fen.insert(I);
}
cout<<ans<<'\n';
return 0;
}
