// 那就是希望。
// 即便需要取模，也是光明。

#include <algorithm>
#include <stdio.h>
#include <vector>
typedef long long llt;
typedef unsigned uint;typedef unsigned long long ullt;
typedef bool bol;typedef char chr;typedef void voi;
typedef double dbl;
template<typename T>bol _max(T&a,T b){return(a<b)?a=b,true:false;}
template<typename T>bol _min(T&a,T b){return(b<a)?a=b,true:false;}
template<typename T>T lowbit(T n){return n&-n;}
template<typename T>T gcd(T a,T b){return b?gcd(b,a%b):a;}
template<typename T>T lcm(T a,T b){return(a!=0||b!=0)?a/gcd(a,b)*b:(T)0;}
template<typename T>T exgcd(T a,T b,T&x,T&y){if(b!=0){T ans=exgcd(b,a%b,y,x);y-=a/b*x;return ans;}else return y=0,x=1,a;}
template<typename T>T power(T base,T index,T mod)
{
    T ans=1%mod;
    while(index)
    {
        if(index&1)ans=ans*base%mod;
        base=base*base%mod,index>>=1;
    }
    return ans;
}
const uint Sigma=27;
chr C[600005];uint Son[Sigma][600005],Fath[21][600005],Len[600005],P[600005],tp;
uint Cnt[600005],Dep[600005];
uint NewNode(uint f)
{
    for(uint i=0;i<Sigma;i++)Son[i][tp]=-1;
    Dep[tp]=Dep[f]+1,Fath[0][tp]=f;
    for(uint i=1;i<=20&&Fath[i-1][tp];i++)Fath[i][tp]=Fath[i-1][Fath[i-1][tp]];
    return tp++;
}
uint kth(uint p,uint k)
{
    for(uint i=0;k>>i;i++)if(k>>i&1)p=Fath[i][p];
    return p;
}
int main()
{
#ifdef MYEE
    freopen("QAQ.in","r",stdin);
    freopen("QAQ.out","w",stdout);
#endif
    C[0]='z'+1;uint n=1;
    while(~(C[n]=getchar())&&C[n]>='a'&&C[n]<='z')C[++n]='z'+1,n++;
    NewNode(0),P[0]=Son[26][0]=NewNode(0);
    for(uint i=1,j=0;i<n;i++)
    {
        if(j+Len[j]<i)P[i]=~Son[C[i]-'a'][0]?Son[C[i]-'a'][0]:Son[C[i]-'a'][0]=NewNode(0);
        else P[i]=kth(P[2*j-i],Len[2*j-i]-(Len[i]=std::min(j+Len[j]-i,Len[2*j-i])));
        while(i>Len[i]&&i+Len[i]+1<n&&C[i-Len[i]-1]==C[i+Len[i]+1])
            Len[i]++,P[i]=~Son[C[i+Len[i]]-'a'][P[i]]?
                    Son[C[i+Len[i]]-'a'][P[i]]:Son[C[i+Len[i]]-'a'][P[i]]=NewNode(P[i]);
        if(i+Len[i]>j+Len[j])j=i;
        Cnt[P[i]]++;
    }
    for(uint i=tp-1;~i;i--)Cnt[Fath[0][i]]+=Cnt[i];
    ullt ans=0;
    for(uint i=1;i<tp;i++)if(i==Son[26][Fath[0][i]])_max(ans,(Dep[i]-2llu)*Cnt[i]);
    printf("%llu\n",ans);
    return 0;
}

// 那就是希望。
// 即便需要取模，也是光明。