#include <bits/stdc++.h>
#define debug
#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 MAXN = 6e5+1 ;
const int ALF= 35 ;
using namespace std ;
// ----------------------------------------------------
//Call Partial
map<string, ll> mapa ;
bool s[110][110] ;
void callPartial(char str[])
{
int n = strlen(str) ;
ll ans = 0 ;
lp(i,0,n) s[i][i] = true ;
lp(i,0,n-1) s[i][i+1] = ( str[i] == str[i+1] ) ;
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] ) ;
lp( i , 0, n )
lp(j,0,n)
if( s[i][j] )
{
string aux ;
aux.resize(j-i+1) ;
lp(k,i,j+1)
aux[k-i] = str[k] ;
if( mapa.find(aux) == mapa.end() )
mapa.insert( mk(aux , 0) ) ;
ll tot = ++ mapa[aux] ;
ans = max( ans , tot * (j-i+1) ) ;
}
printf("%lld\n" , ans ) ;
}
// ----------------------------------------------------
struct Trie
{
int nodes ;
int trie[MAXN][ALF] , lazy[MAXN] , parent[MAXN] ;
ll ans ;
Trie()
{
memset(trie, 0, sizeof trie) ;
memset(lazy,0,sizeof lazy) ;
parent[0] = 0 ;
nodes = 0 ;
ans = 0 ;
}
// The interval becomes [l,r]
int add( char str[] , int l , int r , int address )
{
int cur = address ;
for(int i = l ; i <= r ; i++ )
{
char c = str[i] - 'a' ;
if( trie[cur][c] == 0 )
{
trie[cur][c] = ++ nodes ;
parent[ nodes ] = cur ;
}
cur = trie[cur][c] ;
}
lazy[cur] ++ ;
return cur ;
}
int goUp( int address, int qtd )
{
lp(i,0,qtd) address = parent[address] ;
return address ;
}
ll dfs( int cur , int depth , bool what )
{
ll tempAns = lazy[cur] ;
lp(i,0,30)
if( trie[cur][i] != 0 )
tempAns += dfs(trie[cur][i] , depth+1 , what ) ;
ll multiplier = ( what ? ( depth/2 ) * 2 : ( ( (depth-1)/2 )*2 + 1 ) ) ;
ans = max( ans , tempAns * multiplier ) ;
debug("%d -> %lld %lld\n" , cur , tempAns , multiplier ) ;
return tempAns ;
}
} ;
int n ;
int p[MAXN] , myAd[MAXN] ;
Trie trie ;
char str[MAXN] ;
// ----------------------------------------------------
void findAns()
{
//If I want an odd palindrome
lp(i,0,27)
if( trie.trie[0][i] != 0 )
trie.dfs( trie.trie[0][i] , 1 , 0 ) ;
//If I want an even palindrome
trie.dfs( trie.trie[0][27] , 1 , 1 ) ;
}
void manacher()
{
int center = 0 , right = -1 ;
lp(i,0,n)
{
int rad= 0 , last = 0 , ant = i ;
if( i <= right )
{
rad = min( p[2*center-i] , right - i + 1 ) ;
last = trie.goUp( myAd[2*center-i] , p[2*center-i] - rad ) ;
ant = rad + i ;
}
while( i - rad >= 0 && i + rad < n && str[i-rad] == str[i+rad] )
{ rad ++ ; }
myAd[i] = trie.add(str, ant , i+rad-1 , last ) ;
p[i] = rad ;
debug("With center %d, we have a ratio of %d and the last I used was %d and it became %d\n\n" , i , rad , last , myAd[i]) ;
if( i+rad-1 > right )
{
center = i ;
right = i+rad-1 ;
}
}
}
// ----------------------------------------------------
int main()
{
char difStr[MAXN] ;
scanf(" %s" , difStr ) ;
if( strlen(difStr) <= 100 )
{
callPartial(difStr) ;
return 0 ;
}
n = strlen(difStr)*2 - 1 ;
lp(i,0,n)
{
if( i%2 == 0 ) str[i] = difStr[i/2] ;
else str[i] = '|' ;
}
manacher() ;
findAns() ;
printf("%lld\n" , trie.ans ) ;
}
