#include<bits/stdc++.h>
using namespace std;
#define all(fl) fl.begin(),fl.end()
#define pb push_back
#define fi first
#define se second
#define for1(i,j,k) for(int i=j;i<=k;i++)
#define for2(i,j,k) for(int i=j;i>=k;i--)
#define for3(i,j,k,l) for(int i=j;i<=k;i+=l)
#define lb lower_bound
#define ub upper_bound
#define sz(a) (int)a.size()
#define gcd __gcd
#define lcm(x,y) x*y/__gcd(x,y)
using pii=pair<int,int>;
using pli=pair<long long,int>;
using pil=pair<int,long long>;
struct SA{
int n;
string s;
vector<int>pos,tmp,lcp,sa;
void build(){
for1(i,0,n-1)pos[i]=s[i],sa[i]=i;
for(int gap=1;;gap*=2){
auto cmp=[&](int i,int j){
if (pos[i]!=pos[j])return pos[i]<pos[j];
i+=gap;
j+=gap;
if (i<n&&j<n)return pos[i]<pos[j];
return i>j;
};
sort(all(sa),cmp);
for1(i,0,n-2)tmp[i+1]=tmp[i]+cmp(sa[i],sa[i+1]);
for1(i,0,n-1)pos[sa[i]]=tmp[i];
if (tmp[n-1]==n-1)break;
}
}
void buildLCP(){
for1(i,0,n-1){
if (pos[i]==n-1)continue;
int diff=0;
if (i>0){
diff=max(diff,lcp[pos[i-1]]-1);
}
int j=sa[pos[i]+1];
while (i+diff<n&&j+diff<n&&s[i+diff]==s[j+diff])diff++;
lcp[pos[i]]=diff;
}
}
void resz(string S){
s=S;
n=sz(s);
pos.resize(n);
tmp.resize(n);
sa.resize(n);
lcp.resize(n);
build();
buildLCP();
}
};
struct hashing{
vector<long long>pw,h,rh;
long long base,du;
void build(string s){
base=311;
du=1e9+7;
int n=sz(s);
pw.resize(n+1);
h.resize(n+1);
rh.resize(n+2);
pw[0]=1;
for1(i,1,n)pw[i]=(1ll*pw[i-1]*base)%du;
for1(i,1,n)h[i]=(1ll*h[i-1]*base+s[i-1]-'a'+1)%du;
for2(i,n,1){
rh[i]=(1ll*rh[i+1]*base+s[i-1]-'a'+1)%du;
}
}
long long get(int i,int j){
i++;
j++;
return (1ll*h[j]-1ll*h[i-1]*pw[j-i+1]+1ll*du*du)%du;
}
long long rget(int i,int j){
i++;
j++;
return (1ll*rh[i]-1ll*rh[j+1]*pw[j-i+1]+1ll*du*du)%du;
}
};
const int maxn=3e5+8;
vector<int>d1[maxn],d2[maxn],c[maxn];
int best[maxn],f[maxn];
bool turn[maxn];
long long ans=1;
int findset(int u){
if (f[u]<0)return u;
return f[u]=findset(f[u]);
}
void unite(int u,int v){
u=findset(u),v=findset(v);
if (u==v)return;
if (f[u]>f[v])swap(u,v);
f[u]+=f[v];
f[v]=u;
}
int cc(int u){
u=findset(u);
return abs(f[u]);
}
signed main(){
srand(time(0));
ios_base::sync_with_stdio(0);
cin.tie(0);
//freopen("usaco.INP","r",stdin);
//freopen("usaco.OUT","w",stdout);
string s;
cin>>s;
int n=sz(s);
SA a;
a.resz(s);
hashing b;
b.build(s);
set<int>t1,t2;
set<int>::iterator it;
//cerr<<b.get(1,2)<<" "<<b.rget(4,5);
for2(i,n-1,0){
int l=1,r=min(i,n-(i+1)),p1=0;
while (l<=r){
int mid=(l+r)/2;
//cerr<<mid<<'\n';
if (b.get(i-mid,i-1)==b.rget(i+1,i+mid)){
p1=mid;
l=mid+1;
}
else r=mid-1;
}
if (p1>0){
ans=max(ans,1ll+p1*2);
d1[i-p1].pb(i-1);
t1.insert(i-1);
}
if (i+1<n&&s[i]==s[i+1]){
l=2,r=min(i+1,n-1-(i+1)+1),p1=1;
while (l<=r){
int mid=(l+r)/2;
if (b.get(i-mid+1,i)==b.rget(i+1,i+1+mid-1)){
p1=mid;
l=mid+1;
}
else r=mid-1;
}
t2.insert(i);
ans=max(ans,1ll*2*p1);
//cerr<<i<<" "<<i-p1+1<<'\n';
//if (i==73)cerr<<p1<<'\n';
d2[i-p1+1].pb(i);
}
if (!t1.empty()){
it=t1.end();
it--;
if (*it>=i){
ans=max(ans,1ll+(*it-i+1)*2);
}
if (a.pos[i]!=n-1){
int sz=a.lcp[a.pos[i]]/2;
if (sz*2==a.lcp[a.pos[i]])sz--;
it=t1.upper_bound(i+sz-1);
if (it!=t1.begin()){
it--;
best[i]=max(best[i],(*it-i+1)*2+1);
//cerr<<i<<" "<<best[i]<<'\n';
}
}
}
if (!t2.empty()){
it=t2.end();
it--;
ans=max(ans,1ll*2*(*it-i+1));
//cerr<<i<<" "<<*it<<" "<<*it-i+1<<'\n';
if (a.pos[i]!=n-1){
int sz=a.lcp[a.pos[i]]/2;
it=t2.upper_bound(i+sz-1);
if (it!=t2.begin()){
it--;
//if (i==49)cerr<<*it<<'\n';
best[i]=max(best[i],(*it-i+1)*2);
}
}
}
for(auto v:d1[i]){
t1.erase(v);
}
for(auto v:d2[i]){
//cerr<<i<<" "<<v<<'\n';
//if (v==73)cerr<<i<<'\n';
t2.erase(v);
}
//cout<<i<<" "<<lc<<'\n';
}
for1(i,0,n-2){
f[i]=-1;
c[a.lcp[i]].pb(i);
//cout<<a.sa[i]<<'\n';
//cout<<ia.lcp[i]<<'\n';
}
for2(i,n,1){
for (auto v:c[i]){
if (v>0&&turn[v-1]){
unite(v,v-1);
}
if (v+1<n-1&&turn[v+1]){
unite(v,v+1);
}
ans=max(ans,1ll*(cc(v)+1)*best[a.sa[v]]);
turn[v]=1;
}
}
cout<<ans;
}
