#include <bits/stdc++.h>
#define ll long long
#define enl putchar('\n')
#define all(x) (x).begin(),(x).end()
#define debug(x) printf(" "#x":%d\n",x);
using namespace std;
const int MAXN = 1e6 + 5;
const int inf = 0x3f3f3f3f;
const ll INF = 0x3f3f3f3f3f3f3f3f;
const int mod = 998244353;
typedef pair<int, int> pii;
char buf[1 << 21], * p1 = buf, * p2 = buf, obuf[1 << 21], * o = obuf, of[35];
#define gc()(p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<21,stdin),p1==p2)?EOF:*p1++)
inline ll qpow(ll a, ll n) { ll res = 1; while (n) { if (n & 1)res = res * a % mod; n >>= 1; a = a * a % mod; }return res; }
template <class T = int>inline T read() { T s = 0, f = 1; char c = gc(); for (; !isdigit(c); c = gc())if (c == '-')f = -1; for (; isdigit(c); c = gc())s = s * 10 + c - '0'; return s * f; }
inline void read(int* a, int n) { for (int i = 1; i <= n; ++i)a[i] = read(); }
inline int inal(char* s) { int n = 0; for (s[0] = gc(); !isalpha(s[0]); s[0] = gc()); for (; isalpha(s[n]); s[++n] = gc()); return s[n] = 0, n; }
inline int indi(char* s) { int n = 0; for (s[0] = gc(); !isdigit(s[0]); s[0] = gc()); for (; isdigit(s[n]); s[++n] = gc()); return s[n] = 0, n; }
inline void outd(auto* a, int n) { for (int i = 1; i <= n; ++i)printf("%d ", a[i]); enl; }
int n, m, q;
struct SAM { //最多2n-1个点和3n-4条边
    int len[MAXN << 1], link[MAXN << 1], ch[MAXN << 1][26]; //我们记 longest(v) 为其中最长的一个字符串，记 len(v) 为它的长度。
    int cnt[MAXN << 1];
    int cur, lst, siz;
    SAM() { clear(); }
    void clear() {  //设置起始点S
        memset(ch, 0, sizeof(int) * (siz + 1) * 26);
        len[0] = 0;
        link[0] = -1;
        siz = 0;    //siz设置成0实际上有一个点，方便标记
        lst = cur = 0;
    }
    void extend(int c) {
        lst = cur, cur = ++siz;
        len[cur] = len[lst] + 1;
        cnt[cur] = 1;
        for (; ~lst && !ch[lst][c]; lst = link[lst])ch[lst][c] = cur;

        if (lst == -1) {
            link[cur] = 0;
        } else {
            int q = ch[lst][c];
            if (len[lst] + 1 == len[q]) {
                link[cur] = q;
            } else {        //克隆的点是q(lst的c后继)
                int clone = ++siz;
                link[clone] = link[q];
                len[clone] = len[lst] + 1;
                link[cur] = link[q] = clone;
                for (; ~lst && ch[lst][c] == q; lst = link[lst])ch[lst][c] = clone;
                memcpy(ch[clone], ch[q], sizeof(ch[q]));
            }
        }
    }
}p;
char s[MAXN];
int c[MAXN], rk[MAXN];
ll ans = 0;
void tuopu() {
    for (int i = 1; i <= p.siz; i++) c[p.len[i]]++;
    for (int i = 1; i <= p.siz; i++) c[i] += c[i - 1];
    for (int i = 1; i <= p.siz; i++) rk[c[p.len[i]]--] = i;
    for (int i = p.siz; i >= 1; i--) {
        int u = rk[i], fa = p.link[u];
        if (p.cnt[u] > 1) ans = max(ans, 1ll * p.len[u] * p.cnt[u]);
        p.cnt[fa] += p.cnt[u];
    }
}
void solve() {
    n = inal(s + 1);
    for (int i = 1; i <= n; i++) p.extend(s[i] - 'a');
    tuopu();
    printf("%lld\n", ans);
}
signed main(signed argc, char const* argv[]) {
    clock_t c1 = clock();
#ifdef LOCAL
    freopen("in.in", "r", stdin);
    freopen("out.out", "w", stdout);
#endif
    //=============================================================
    int TxT = 1;
    // TxT = read();
    while (TxT--)
        solve();
    //=============================================================
#ifdef LOCAL
    end :
    cerr << "Time Used:" << clock() - c1 << "ms" << endl;
#endif
    return 0;
}