#include<iostream>

 #include<cstdio>

 #include<cstdlib>

 #include<cmath>

 #include<algorithm>

 #include<cstring>

 #include<vector>

 #include<queue>

 #include<map>

 #define rep(i,s,t) for(register int i=(s);i<=(t);++i)

 #define dwn(i,s,t) for(register int i=(s);i>=(t);--i)

 #define ren for(register int i=fst[x];i;i=nxt[i])

 #define Fill(x,t) memset(x,t,sizeof(x))

 #define ll long long

 #define inf 2139062143

 #define MAXN 2001000

 using namespace std;

 char s[MAXN];

 int n,rt,lst,tr[MAXN][],tot,sz[MAXN],mxlen[MAXN],rnk[MAXN],cnt[MAXN],fa[MAXN];

 ll ans;

 inline void extend(int c)

 {

     int p=lst,np=lst=++tot;mxlen[np]=mxlen[p]+,sz[np]=;

     for(;p&&!tr[p][c];p=fa[p]) tr[p][c]=np;

     if(!p) {fa[np]=rt;return ;}

     int q=tr[p][c];if(mxlen[q]==mxlen[p]+) {fa[np]=q;return ;}

     int nq=++tot;mxlen[nq]=mxlen[p]+;

     memcpy(tr[nq],tr[q],sizeof(tr[nq]));

     fa[nq]=fa[q],fa[np]=fa[q]=nq;

     for(;p&&tr[p][c]==q;p=fa[p]) tr[p][c]=nq;

 }

 void build()

 {

     rep(i,,tot) cnt[mxlen[i]]++;rep(i,,n) cnt[i]+=cnt[i-];

     rep(i,,tot) rnk[cnt[mxlen[i]]--]=i;int p;

     dwn(i,tot,)

     {

         p=rnk[i],sz[fa[p]]+=sz[p];

         if(sz[p]>) ans=max(ans,1LL*sz[p]*mxlen[p]);

     }

 }

 int main()

 {

     rt=lst=tot=;scanf("%s",s+);n=strlen(s+);

     rep(i,,n) extend(s[i]-'a');

     build();printf("%lld\n",ans);

 }