#include <bits/stdc++.h>
#define endl '\n'
using namespace std;
const unsigned long long B1 = 131, B2 = 31, MOD = (1e9) + 696969;
const int N = 300007;
struct rolling_hash {
unsigned long long h1,h2;
rolling_hash(): h1(0), h2(0) {}
void append(char a) {
h1*=B1;
h1+=a-'a'+1;
h2*=B2;
h2+=a-'a'+1;
h2%=MOD;
}
bool operator ==(const rolling_hash &a) const {
return h2==a.h2;
}
bool operator <(const rolling_hash &a) const {
return h2<a.h2;
}
};
struct item {
rolling_hash hash;
int from,to;
item(){}
item(rolling_hash a, int b, int c): hash(a), from(b), to(c) {}
bool operator <(const item &a) const {
return to-from+1==a.to-a.from+1 ? hash<a.hash : to-from+1>a.to-a.from+1;
}
};
int n;
char a[N];
unsigned long long pw1[N],pw2[N];
rolling_hash ph[N],sh[N];
map < rolling_hash, pair < int, int > > interval;
map < rolling_hash, int > current_cnt;
set < item > s;
long long ans;
rolling_hash get_prefix_hash(rolling_hash *a, int l, int r) {
rolling_hash hl=a[l-1],hr=a[r];
hl.h1*=pw1[r-l+1];
hl.h2*=pw2[r-l+1];
hl.h2%=MOD;
hr.h1-=hl.h1;
hr.h2-=hl.h2;
hr.h2+=MOD;
hr.h2%=MOD;
return hr;
}
rolling_hash get_suffix_hash(rolling_hash *a, int l, int r) {
rolling_hash hl=a[l],hr=a[r+1];
hr.h1*=pw1[r-l+1];
hr.h2*=pw2[r-l+1];
hr.h2%=MOD;
hl.h1-=hr.h1;
hl.h2-=hr.h2;
hl.h2+=MOD;
hl.h2%=MOD;
return hl;
}
bool is_palindrome(int l, int r) {
return get_prefix_hash(ph,l,r)==get_suffix_hash(sh,l,r);
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int i,j;
rolling_hash h;
pw1[0]=pw2[0]=1;
for(i=1;i<N;i++) {
pw1[i]=pw1[i-1]*B1;
pw2[i]=pw2[i-1]*B2%MOD;
}
scanf("%s", a+1);
n=strlen(a+1);
h=rolling_hash();
for(i=1;i<=n;i++) {
h.append(a[i]);
ph[i]=h;
}
h=rolling_hash();
for(i=n;i>=1;i--) {
h.append(a[i]);
sh[i]=h;
}
for(i=1;i<=n;i++) {
int left=0,right=min(i,n-i+1),middle;
while(right-left>1) {
middle=(left+right)/2;
if(is_palindrome(i-middle,i+middle)) left=middle;
else right=middle;
}
for(j=left;j>=0;j--) {
h=get_prefix_hash(ph,i-j,i+j);
if(interval.find(h)!=interval.end()) break;
interval[h]=make_pair(i-j,i+j);
}
h=get_prefix_hash(ph,i-left,i+left);
++current_cnt[h];
}
for(i=1;i<n;i++) if(a[i]==a[i+1]) {
int left=0,right=min(i,n-i),middle;
while(right-left>1) {
middle=(left+right)/2;
if(is_palindrome(i-middle,i+1+middle)) left=middle;
else right=middle;
}
for(j=left;j>=0;j--) {
h=get_prefix_hash(ph,i-j,i+1+j);
if(interval.find(h)!=interval.end()) break;
interval[h]=make_pair(i-j,i+1+j);
}
h=get_prefix_hash(ph,i-left,i+1+left);
++current_cnt[h];
}
for(map < rolling_hash, int >::iterator it=current_cnt.begin();it!=current_cnt.end();it++) {
h=it->first;
pair < int, int > seg=interval[h];
s.insert(item(h,seg.first,seg.second));
}
while(!s.empty()) {
item curr=*s.begin();
s.erase(s.begin());
int cnt=current_cnt[curr.hash];
ans=max(ans,cnt*1ll*(curr.to-curr.from+1));
if(curr.to-curr.from+1>2) {
curr.hash=get_prefix_hash(ph,curr.from+1,curr.to-1);
pair < int, int > seg=interval[curr.hash];
curr.from=seg.first;
curr.to=seg.second;
current_cnt[curr.hash]+=cnt;
s.insert(curr);
}
}
printf("%lld\n", ans);
return 0;
}
