#include<bits/stdc++.h>
#define For(i,a,b) for(int i=(a);i<=(b);++i)
#define Rep(i,a,b) for(int i=(a);i>=(b);--i)
#define int long long
using namespace std;
inline int read()
{
    char c=getchar();int x=0;bool f=0;
    for(;!isdigit(c);c=getchar())f^=!(c^45);
    for(;isdigit(c);c=getchar())x=(x<<1)+(x<<3)+(c^48);
    if(f)x=-x;return x;
}

#define mod 998244353
struct modint{
	int x;
	modint(int o=0){x=o;}
	modint &operator = (int o){return x=o,*this;}
	modint &operator +=(modint o){return x=x+o.x>=mod?x+o.x-mod:x+o.x,*this;}
	modint &operator -=(modint o){return x=x-o.x<0?x-o.x+mod:x-o.x,*this;}
	modint &operator *=(modint o){return x=1ll*x*o.x%mod,*this;}
	modint &operator ^=(int b){
		modint a=*this,c=1;
		for(;b;b>>=1,a*=a)if(b&1)c*=a;
		return x=c.x,*this;
	}
	modint &operator /=(modint o){return *this *=o^=mod-2;}
	friend modint operator +(modint a,modint b){return a+=b;}
	friend modint operator -(modint a,modint b){return a-=b;}
	friend modint operator *(modint a,modint b){return a*=b;}
	friend modint operator /(modint a,modint b){return a/=b;}
	friend modint operator ^(modint a,int b){return a^=b;}
	friend bool operator ==(modint a,int b){return a.x==b;}
	friend bool operator !=(modint a,int b){return a.x!=b;}
	bool operator ! () {return !x;}
	modint operator - () {return x?mod-x:0;}
	bool operator <(const modint&b)const{return x<b.x;}
};
inline modint qpow(modint x,int y){return x^y;}

vector<modint> fac,ifac,iv;
inline void initC(int n)
{
	if(iv.empty())fac=ifac=iv=vector<modint>(2,1);
	int m=iv.size(); ++n;
	if(m>=n)return;
	iv.resize(n),fac.resize(n),ifac.resize(n);
	For(i,m,n-1){
		iv[i]=iv[mod%i]*(mod-mod/i);
		fac[i]=fac[i-1]*i,ifac[i]=ifac[i-1]*iv[i];
	}
}
inline modint C(int n,int m){
	if(m<0||n<m)return 0;
	return initC(n),fac[n]*ifac[m]*ifac[n-m];
}
inline modint sign(int n){return (n&1)?(mod-1):(1);}

#define fi first
#define se second
#define pb push_back
#define mkp make_pair
typedef pair<int,int>pii;
typedef vector<int>vi;
 
#define maxn 2000005
#define inf 0x3f3f3f3f

char s[maxn];
int ch[maxn][26],len[maxn],sz[maxn],fa[maxn],tot=1,lst=1;
void append(int c){
	int u=++tot,p=lst;
	sz[u]=1; len[u]=len[p]+1;
	for(;p&&!ch[p][c];p=fa[p])ch[p][c]=u;
	if(!p)fa[u]=1;
	else{
		int q=ch[p][c];
		if(len[q]==len[p]+1)fa[u]=q;
		else{
			int nq=++tot;
			len[nq]=len[p]+1; fa[nq]=fa[q];
			memcpy(ch[nq],ch[q],sizeof ch[q]);
			for(;p&&ch[p][c]==q;p=fa[p])ch[p][c]=nq;
			fa[q]=fa[u]=nq;
		}
	}lst=u;
}
int b[maxn],c[maxn];
void radixsort(){
	For(i,1,tot)++c[len[i]];
	For(i,1,tot)c[i]+=c[i-1];
	For(i,1,tot)b[c[len[i]]--]=i;
	Rep(i,tot,1)sz[fa[b[i]]]+=sz[b[i]]; 
}

signed main()
{
	cin>>s+1;
	int n=strlen(s+1);
	For(i,1,n)append(s[i]-'a');
	radixsort();
	long long res=0;
	For(i,1,tot)if(sz[i]>1)res=max(res,1ll*sz[i]*len[i]);
	cout<<res;
	return 0;
}
/*
ctubdigkmrvmkrrdzshhtyghlcjxsowqlvueuaqtrgubtotqheqickwpgwmstqohkczayodrjpcdmkfahhtazvbgrvmkgfvwxgwo
*/