// Problem: No.2606 Mirror Relay
// Contest: yukicoder
// URL: https://yukicoder.me/problems/no/2606
// Memory Limit: 512 MB
// Time Limit: 2000 ms

#include<bits/stdc++.h>
#define debug(x) cerr<<(#x)<<" "<<(x)<<endl
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
#define pii pair<ll,ll>
#define rep(i,a,b) for(ll i=(a);i<=(b);++i)
#define per(i,a,b) for(ll i=(a);i>=(b);--i)
using namespace std;
bool Mbe; 
ll read(){
	ll x=0,f=1;char ch=getchar();
	while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
	while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
	return x*f;
}
void write(ll x){
	if(x<0)putchar('-'),x=-x;
	if(x>9)write(x/10);
	putchar(x%10+'0');
}
const ll N=1e6+9;
ll n,p,q,fail[N],cnt[N],len[N],tot,lst,ch[N][26],pos[N],sum[N];
char s[N];
ll New(ll x){
    len[++tot]=x;
    return tot;
}
ll Fail(ll x,ll i){
    while(s[i-len[x]-1]!=s[i])x=fail[x];
    return x;
}
bool Med;
int main(){
	cerr<<fabs(&Med-&Mbe)/1048576.0<<"MB\n";
	scanf("%s",s+1);
	n=strlen(s+1);
	reverse(s+1,s+n+1);
	s[0]=-1,fail[0]=1,lst=0;
    len[0]=0,len[1]=-1,tot=1;
    rep(i,1,n){
        ll v=s[i]-'a';
        p=Fail(lst,i);
        if(!ch[p][v]){
            q=New(len[p]+2);
            fail[q]=ch[Fail(fail[p],i)][v]; 
            ch[p][v]=q;
        }
        lst=ch[p][v];
        ++cnt[lst];
        pos[i]=lst;
    }
    per(i,tot,1)cnt[fail[i]]+=cnt[i];
    rep(i,1,tot)sum[i]=cnt[i]*len[i]+sum[fail[i]];
    write(*max_element(sum+1,sum+tot+1));
	return 0;
}