#include <bits/stdc++.h>
using namespace std;
int const N=3e5+5;
struct Node
{
int len;
int start,end;
int child[26]={0};
int suffix;
};
Node root1,root2;
Node tree[N];
long long cnt[N];
int curnode,ptr;
string s;
void insert_char(int k){
// cout<<k<<endl;
int tmp=curnode;
while(!(k-tree[tmp].len>=1 && s[k]==s[k-(tree[tmp].len+1)]))
tmp=tree[tmp].suffix;
if(tree[tmp].child[s[k]-'a']!=0){
curnode=tree[tmp].child[s[k]-'a'];
return;
}
ptr++;
tree[tmp].child[s[k]-'a']=ptr;
tree[ptr].len=tree[tmp].len+2;
tree[ptr].end=k;
tree[ptr].start=k-(tree[ptr].len)+1;
tmp=tree[tmp].suffix;
curnode=ptr;
if(tree[curnode].len==1){//root2 will be suffix
tree[curnode].suffix=2;
return;
}
while(!(k-tree[tmp].len>=1 && s[k]==s[k-(tree[tmp].len+1)]))
tmp=tree[tmp].suffix;
tree[curnode].suffix=tree[tmp].child[s[k]-'a'];
return;
}
int main(){
root1.len=-1;
root1.suffix=1;
root2.len=0;
root2.suffix=1;
tree[1]=root1;
tree[2]=root2;
ptr=2;
curnode=1;
cin>>s;
int n=s.length();
for (int i = 0; i < n; ++i)
insert_char(i);
// cout<<ptr<<endl;
vector<pair<int,int>> v;
for (int i = 3; i <=ptr; ++i)
{
cnt[i]=1;
v.push_back({-tree[i].len,i});
}
sort(v.begin(), v.end());
for(auto p:v)
cnt[tree[p.second].suffix]+=cnt[p.second];
long long mx=0;
for(int i=3;i<=ptr;i++)
mx=max(mx,cnt[i]*(tree[i].len));
cout<<mx<<endl;
return 0;
}
