#include<cstdio>

#include<cstring>

#include<algorithm>

using namespace std;

#define N 300001

char ss[N];

int s[N];

int tot=,last;

int fail[N],len[N],cnt[N];

int tr[N][];

int p,c,np,t;

void extend(int i)

{

    p=last; c=s[i];

    while(s[i--len[p]]!=c)

        p=fail[p];

    if(!tr[p][c])

    {

        np=++tot;

        len[np]=len[p]+;

        t=fail[p];

        while(s[i--len[t]]!=c) t=fail[t];

        fail[np]=tr[t][c];

        tr[p][c]=np;

    }

    else np=tr[p][c];

    cnt[last=np]++;

}

int main()

{

    scanf("%ss",ss+);

    int n=strlen(ss+);

    s[]=-;

    for(int i=;i<=n;++i) s[i]=ss[i]-'a';

    fail[]=; len[]=-;

    for(int i=;i<=n;++i)

        extend(i);

    for(int i=tot;i>;--i) cnt[fail[i]]+=cnt[i];

    long long ans=;

    for(int i=;i<=tot;++i) ans=max(ans,1LL*cnt[i]*len[i]);

    printf("%lld",ans);

}