#include<bits/stdc++.h>
using namespace std;
#define ll long long
const int N = 2e6+5;
struct Node{
    int len,fa;
    //len表示该结点的最大后缀长度，fa代表绿边。
    int son[26];
}node[N];
ll f[N];
ll tot = 1,last = 1,ans;
vector<int> g[N];
void dfs(int u){
    for(int i = 0; i < g[u].size(); i++){
        int j = g[u][i];
        dfs(j);
        f[u]+=f[j];
    }
    if(f[u] > 1) ans = max(ans,f[u]*node[u].len);
}
char s[N];
//epos[i]代表以i状态的集合大小。
void extend(int c){
    int p = last,np = last = ++tot;
    f[tot] = 1;
    node[np].len = node[p].len+1;
    for(; p&&!node[p].son[c]; p = node[p].fa) node[p].son[c] = np;
    if(!p) node[np].fa = 1;
    else{
        int q = node[p].son[c];
        if(node[q].len == node[p].len+1) node[np].fa = q;
        else{
            int nq = ++tot;
            node[nq] = node[q],node[nq].len = node[p].len+1;
            node[q].fa = node[np].fa = nq;
            for(;p&&node[p].son[c] == q;p = node[p].fa) node[p].son[c] = nq;
        }
    }
}
signed main(){
    scanf("%s",s);
    for(int i = 0; s[i]; i++) extend(s[i]-'a');
    for(int i = 2; i <= tot; i++) g[node[i].fa].push_back(i);
    dfs(1);
    cout << ans << '\n';
}