#include<bits/stdc++.h>
using namespace std;
namespace my_std{
	#define ll long long
	#define bl bool
	ll my_pow(ll a,ll b,ll mod){
		ll res=1;
		if(!b) return 1;
		while(b){
			if(b&1) res=(res*a)%mod;
			a=(a*a)%mod;
			b>>=1;
		}
		return res;
	}
	ll qpow(ll a,ll b){
		ll res=1;
		if(!b) return 1;
		while(b){
			if(b&1) res*=a;
			a*=a;
			b>>=1;
		}
		return res;
	}
	#define db double
	#define pf printf
	#define pc putchar
	#define fr(i,x,y) for(register ll i=(x);i<=(y);i++)
	#define pfr(i,x,y) for(register ll i=(x);i>=(y);i--)
	#define go(u) for(ll i=head[u];i;i=e[i].nxt)
	#define enter pc('\n')
	#define space pc(' ')
	#define fir first
	#define sec second
	#define MP make_pair
	#define il inline
	#define inf 1e18
	#define random(x) rand()*rand()%(x)
	#define inv(a,mod) my_pow((a),(mod-2),(mod))
	il ll read(){
		ll sum=0,f=1;
		char ch=0;
		while(!isdigit(ch)){
			if(ch=='-') f=-1;
			ch=getchar();
		}
		while(isdigit(ch)){
			sum=sum*10+(ch^48);
			ch=getchar();
		}
		return sum*f;
	}
	il void write(ll x){
		if(x<0){
			x=-x;
			pc('-');
		}
		if(x>9) write(x/10);
		pc(x%10+'0');
	}
	il void writeln(ll x){
		write(x);
		enter;
	}
	il void writesp(ll x){
		write(x);
		space;
	}
}
using namespace my_std;
ll n,head[400040],cnt=0,ch[400040][26],mxl[400040],lnk[400040],siz[400040],lst=0,tot=0,ans=0;
char s[200020];
struct node{
	ll nxt,to;
}e[400040];
void add(ll u,ll v){
	e[++cnt].nxt=head[u];
	e[cnt].to=v;
	head[u]=cnt;
}
void ins(char c){
	ll now=lst;
	lst=++tot;
	mxl[tot]=mxl[now]+1;
	siz[tot]=1;
	while(!ch[now][c-'a']){
		ch[now][c-'a']=tot;
		if(!now){
			lnk[tot]=now;
			return;
		}
		now=lnk[now];
	}
	ll tmp=ch[now][c-'a'];
	if(mxl[tmp]==(mxl[now]+1)) lnk[tot]=tmp;
	else{
		mxl[++tot]=mxl[now]+1;
		lnk[tot]=lnk[tmp];
		lnk[tmp]=tot;
		while(ch[now][c-'a']==tmp){
			ch[now][c-'a']=tot;
			if(!now) break;
			now=lnk[now];
		}
		fr(i,0,25) ch[tot][i]=ch[tmp][i];
		lnk[lst]=tot;
	}
}
void dfs(ll u){
	go(u){
		ll v=e[i].to;
		dfs(v);
		siz[u]+=siz[v];
	}
	if(siz[u]>1) ans=max(ans,mxl[u]*siz[u]);
}
int main(){
	scanf("%s",s+1);
	n=strlen(s+1);
	fr(i,1,n) ins(s[i]);
	fr(i,1,tot) add(lnk[i],i);
	dfs(0);
	write(ans);
}