#include<bits/stdc++.h>
#include<unordered_map>
using namespace std;
typedef __int128 ll;
const ll x=31;
const ll mod=1000000000000000009;
ll hasz[300010][2];
ll pot[300010];
ll odw[300010];
string s;
ll spr(bool b,int kt){
if(kt<0||kt>=s.size())return 0;
return hasz[kt][b];
}
void haszuj(){
for(int i=0;i<s.size();i++){
hasz[i][0]=(spr(0,i-1)*x+s[i]-'a'+1)%mod;
hasz[i][1]=((s[i]-'a'+1)*pot[i]+spr(1,i-1))%mod;
}
return;
}
ll ferm(ll xx){
ll wyn=1,pott=mod-2;
while(pott){
if(pott%2)wyn*=xx;
xx*=xx;
xx%=mod;
wyn%=mod;
pott/=2;
}
return wyn;
}
int bs(int a,bool b){
ll vp=1,vs,vk=s.size(),od=0;
while(vp<=vk){
vs=(vp+vk)/2;
if(a+vs-1>=s.size()||a-vs+(b^1)<0)vk=vs-1;
else{
/*if(a==154){
if(vs==1)cout<<(long long)((hasz[a+vs-1][0]-(spr(0,a-vs+(b^1)-1)*pot[vs+vs-(b^1)-1+1])%mod+mod)%mod)<<' '<<(long long)((((hasz[a+vs-1][1]-spr(1,a-vs+(b^1)-1))*odw[a-vs+(b^1)]))%mod)<<'\n';
}*/
if((hasz[a+vs-1][0]-(spr(0,a-vs+(b^1)-1)*pot[vs+vs-(b^1)-1+1])%mod+mod)%mod==(((hasz[a+vs-1][1]-spr(1,a-vs+(b^1)-1)+mod)*odw[a-vs+(b^1)]))%mod){
vp=vs+1;
od=vs;
}
else vk=vs-1;
}
}
return od;
}
unordered_map<long long,pair<pair<ll,ll>,ll> >m[2];//klucz - hasz polowy palindromu, parzystosc //// wartosci - glebokosc, ile(suma prefixowa), skad
void upd(int a,int il,bool b){
int pom=il;
if(il==0)return;
while(m[b].find((hasz[a+il-1][0]-(spr(0,a-1)*pot[il])%mod+mod)%mod)==m[b].end()){
if(il<=1){
m[b][((hasz[a+il-1][0]-(spr(0,a-1)*pot[il])%mod)+mod)%mod]={{1,0},0};
//cout<<"x ";
break;
}
il--;
}
//cout<<(long long)((hasz[a+il-1][0]-spr(0,a-1)*pot[il])%mod)<<' ';
for(int i=il+1;i<=pom;i++){
m[b][(hasz[a+i-1][0]-(spr(0,a-1)*pot[i])%mod+mod)%mod]={{m[b][(hasz[a+i-1-1][0]-(spr(0,a-1)*pot[i-1])%mod+mod)%mod].first.first+1,0},(hasz[a+i-1-1][0]-(spr(0,a-1)*pot[i-1])%mod+mod)%mod};
// cout<<(long long)((hasz[a+i-1][0]-spr(0,a-1)*pot[i])%mod)<<' ';
}
//cout<<'\n';
m[b][(hasz[a+pom-1][0]-(spr(0,a-1)*pot[pom])%mod+mod)%mod].first.second++;
//cout<<(long long)((hasz[a+pom-1][0]-spr(0,a-1)*pot[pom])%mod)<<' '<<(long long)m[b][(hasz[a+pom-1][0]-spr(0,a-1)*pot[pom])%mod].first.second<<'\n';
//cout<<b<<' '<<"dodaje\n";
return;
}
pair<ll,ll>deefes(ll a,bool b){
ll sum=m[b][a].first.second,wyn=0;
//cout<<"deefes wchodzi do hasza: "<<(long long)a<<'\n';
for(int i='a';i<='z';i++){
// cout<<"z "<<(long long)a<<" do "<<(long long)((a*x+i-'a'+1)%mod)<<'\n';
if(m[b].find((a*x+i-'a'+1)%mod)!=m[b].end()){
pair<ll,ll>p=deefes((a*x+i-'a'+1)%mod,b);
wyn=max(wyn,p.first);
sum+=p.second;
}
}
//cout<<(long long)a<<' '<<b<<' '<<(long long)m[b][a].first.first<<' '<<(long long)sum<<'\n';
return {max((m[b][a].first.first*2-(b^1))*sum,wyn),sum};
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin>>s;
//cout<<s.size()<<'\n';
pot[0]=1;
for(int i=1;i<=s.size();i++)pot[i]=(pot[i-1]*x)%mod;
odw[s.size()]=ferm(pot[s.size()]);
for(int i=s.size()-1;i>=0;i--)odw[i]=(odw[i+1]*x)%mod;
haszuj();
for(int i=0;i<s.size();i++){
for(int j=0;j<2;j++){
int a=bs(i,j);
//cout<<i<<' '<<j<<' '<<a<<'\n';
upd(i,a,j);
}
}
m[0][0]={{0,0},0};
m[1][0]={{0,0},0};
cout<<(long long)max(deefes(0,0).first,deefes(0,1).first);
return 0;
}
