LG3804

#include<bits/stdc++.h>

using namespace std;

#define gc c=getchar()
#define r(x) read(x)
#define ll long long

template<typename T>
inline void read(T&x){
    x=0;T k=1;char gc;
    while(!isdigit(c)){if(c=='-')k=-1;gc;}
    while(isdigit(c)){x=x*10+c-'0';gc;}x*=k;
}

const int N=2e6+7;

int Max[N];
int Min[N];
int to[N][26];
int fa[N];
int siz[N];

int tot;

inline int NewNode(int mx,int mi,int *tr,int su){
    ++tot;
    Max[tot]=mx;
    Min[tot]=mi;
    if(tr!=NULL)memcpy(to[tot],tr,26<<2);
    fa[tot]=su;
    return tot;
}

inline int extend(int u,int c){
    int t=NewNode(Max[u]+1,0,NULL,0);
    siz[t]=1;
    for(;u&&!to[u][c];u=fa[u])to[u][c]=t;
    if(!u){
        Min[t]=1;
        fa[t]=1;
        return t;
    }
    int v=to[u][c];
    if(Max[v]==Max[u]+1){
        Min[t]=Max[v]+1;
        fa[t]=v;
        return t;
    }
    int x=NewNode(Max[u]+1,0,to[v],fa[v]);
    Min[t]=Min[v]=Max[x]+1;
    fa[t]=fa[v]=x;
    Min[x]=Min[fa[x]]+1;
    for(;u&&to[u][c]==v;u=fa[u])to[u][c]=x;
    return t;
}

char s[N];
int deg[N];
int ans[N];
queue<int>Q;

int main(){
    scanf("%s",s);
    int n=strlen(s);
    int lst=NewNode(0,0,NULL,0);
    for(int i=0;i<n;++i){
        lst=extend(lst,s[i]-'a');
    }
    for(int i=2;i<=tot;++i){
        deg[fa[i]]++;
    }
    for(int i=1;i<=tot;++i){
        if(!deg[i]){
            Q.push(i);
        }
    }
    while(!Q.empty()){
        int x=Q.front();Q.pop();
        siz[fa[x]]+=siz[x];
        if(fa[x]&&!--deg[fa[x]]){
            Q.push(fa[x]);
        }
    }
    ll ans=0;
    for(int i=2;i<=tot;++i){
        if(siz[i]>1){
            ans=max(ans,(ll)siz[i]*Max[i]);
        }
    }
    printf("%lld\n",ans);
    return 0;
}