#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx,avx2,fma")
#define all(v) v.begin(),v.end()
#define compress(v) v.erase(unique(all(v)),v.end())
#define lbx(v,x) lower_bound(all(v),x)-v.begin()
#define ubx(v,x) upper_bound(all(v),x)-v.begin()
#define maxx(a,b) a=max(a,b)
#define minn(a,b) a=min(a,b)
#define for0(i,n) for (int i=0; i<n; i++)
#define for1(i,n) for (int i=1; i<=n; i++)
#define forr(i,l,r) for (int i=l; i<=r; i++)
#define sz(v) (int)v.size()
using namespace std;
typedef long long ll;
const ll B1=1777;
const ll B2=7499;
const ll P1=123456791;
const ll P2=1104110479;
const int MAX=300000;
ll PowB1[MAX+1],PowB2[MAX+1],IPowB1[MAX+1],IPowB2[MAX+1];
ll myPow(ll a,ll b,ll mod){
ll ret=1;
while (b){
if (b&1)
ret=ret*a%mod;
a=a*a%mod;
b>>=1;
}
return ret;
}
int N;
string S,A;
int P[MAX*2];
ll H1[MAX+1],H2[MAX+1];
map<pair<ll,ll>,int> Map;
int CntHash;
vector<int> Adj[MAX+1];
int L[MAX+1];
int Cnt[MAX+1];
bool Visited[MAX+1];
pair<ll,ll> getHash(int l,int r){
return {(H1[r]-(l?H1[l-1]:0)+P1)%P1*IPowB1[l]%P1,(H2[r]-(l?H2[l-1]:0)+P2)%P2*IPowB2[l]%P2};
}
int getIdx(pair<ll,ll> h,int l,int r){
if (Map.find(h)!=Map.end())
return Map[h];
Map[h]=++CntHash;
L[CntHash]=r-l+1;
return CntHash;
}
void solve(int l,int r){
if (l>r)
return;
pair<ll,ll> h=getHash(l,r);
int ih=getIdx(h,l,r);
Cnt[ih]++;
if (ih!=CntHash)
return;
while (l+1<=r-1){
pair<ll,ll> nxt=getHash(l+1,r-1);
int inxt=getIdx(nxt,l+1,r-1);
bool flag=(inxt!=CntHash);
Adj[inxt].push_back(ih);
if (flag)
break;
h=nxt;
ih=inxt;
l++;
r--;
}
}
int dfs(int v){
if (Visited[v])
return Cnt[v];
Visited[v]=true;
for (int i:Adj[v])
Cnt[v]+=dfs(i);
return Cnt[v];
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
PowB1[0]=PowB2[0]=1;
for1(i,MAX){
PowB1[i]=PowB1[i-1]*B1%P1;
PowB2[i]=PowB2[i-1]*B2%P2;
}
IPowB1[MAX]=myPow(PowB1[MAX],P1-2,P1);
IPowB2[MAX]=myPow(PowB2[MAX],P2-2,P2);
for (int i=MAX; i; i--){
IPowB1[i-1]=IPowB1[i]*B1%P1;
IPowB2[i-1]=IPowB2[i]*B2%P2;
}
cin>>S;
N=sz(S);
for0(i,N){
H1[i]=((i?H1[i-1]:0)+S[i]*PowB1[i]%P1)%P1;
H2[i]=((i?H2[i-1]:0)+S[i]*PowB2[i]%P2)%P2;
}
A.push_back(S[0]);
for1(i,N-1){
A.push_back('.');
A.push_back(S[i]);
}
for (int i=0,r=-1,k=-1; i<N*2-1; i++){
if (i<=r)
P[i]=min(P[2*k-i],r-i);
while (i-P[i]-1>=0&&i+P[i]+1<N*2-1&&A[i-P[i]-1]==A[i+P[i]+1])
P[i]++;
if (r<i+P[i]){
r=i+P[i];
k=i;
}
if (i&1){
int len=(P[i]+1)/2;
solve(i/2-len+1,i/2+len);
}
else{
int len=P[i]/2;
solve(i/2-len,i/2+len);
}
}
assert(CntHash<=N);
ll ans=0;
for1(i,CntHash)
maxx(ans,(ll)L[i]*dfs(i));
cout<<ans;
return 0;
}
