#include <bits/stdc++.h>
#define lp(i,a,b) for(int i=a;i<b;i++)
#define pii pair<int,int>
#define ll long long
#define ff first
#define ss second
#define pb push_back
#define mk make_pair
const int inf = 0x3f3f3f3f ;
const int MAXN = 1010 ;
const int ALF = 30 ;
const int SZTRIE = MAXN*MAXN ;
using namespace std ;
//Se der errado, checar o limite da trie
int n ;
ll ans = 0 ;
string str ;
bool s[MAXN][MAXN] ;
map<string, ll> mapa ;
void findPalindrome()
{
lp(i,0,n) s[i][i] = true ;
lp(i,0,n-1)
if( str[i] == str[i+1] ) s[i][i+1] = true ;
lp(i,2,n)
for(int j = 0 ; j + i < n ; j++ )
s[j][j+i] = ( s[j+1][j+i-1] && (str[j]==str[j+i]) ) ;
}
int main()
{
ios_base::sync_with_stdio(false) ;
cin.tie(NULL) ;
cin>>str ;
n = str.size() ;
findPalindrome() ;
lp(i,0,n)
lp(j,i,n)
if(s[i][j])
{
string Str ;
Str.resize(j-i+1) ;
for(int k = i , ind = 0 ; k <= j ; k++ , ind++ ) Str[ind] = str[k] ;
if(mapa.find(Str) == mapa.end() )
mapa.insert(mk(Str,0)) ;
ll tot = ++mapa[Str] ;
ans = max(ans, tot*(j-i+1)) ;
}
cout<<ans<<endl;
}
