//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#define speed ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
#define ll long long
#define mp make_pair
#define f first
#define s second
#define pill pair<ll, ll>
#define pb push_back
using namespace std;
const ll N = 3e5 + 10;
int n;
string b;
int a[21][N], suf[N];
vector<pair<int, int>> x;
vector<int> srt[N];
vector<int> srt2[N];
void sufmas() {
for(int j = 1; j <= n; j++) {
a[0][j] = b[j - 1] - 'a' + 1;
}
ll k = __lg(n - 1) + 1;
for(int j = 1; j <= k; j++) {
int r = 0, r2 = 0;
for(int i = 1; i <= n; i++) {
int z = ((i + (1<<(j-1)))>n ? 0 : a[j - 1][i + (1<<(j-1))]);
r = max(z, r);
r2 = max(r2, a[j - 1][i]);
srt[z].pb(i);
}
for(int i = 0; i <= r; i++)
for(auto u : srt[i])
srt2[a[j - 1][u]].pb(u);
ll cnt = 0;
for(int i = 1; i <= r2; i++) {
ll lst = -2;
for(auto u : srt2[i]) {
if(a[j - 1][u +(1<<(j-1))] != lst)
lst = a[j - 1][u +(1<<(j-1))], cnt++;
a[j][u] = cnt, suf[u] = cnt;
}
srt2[i].clear(), srt[i].clear();
}
}
for(int i = 1; i <= n; i++)
x.pb(mp(suf[i], i));
sort(x.begin(), x.end());
}
int dp[N], dp2[N];
vector<pair<ll, pill>> que;
void manaker() {
for(int i = 1, r = 0, m = 0; i <= n; i++) {
if(i <= r)
dp[i] = min(r - i, dp[m - i + m]);
while(i + dp[i] <= n && i > dp[i] && b[i + dp[i] - 1] == b[i - dp[i] - 1])
dp[i]++;
if(i + dp[i] - 1 > r)
r = i + dp[i] - 1, m = i;
}
for(int i = 1, r = 0, m = 0; i <= n; i++) {
if(i <= r)
dp2[i] = min(r - i, dp2[m - (i - m - 1) - 1]);
while(i + dp2[i] + 1 <= n && i > dp2[i] && b[i + dp2[i]] == b[i - dp2[i] - 1])
dp2[i]++;
if(i + dp2[i] > r)
r = i + dp2[i], m = i;
}
queue<pill> r;
for(int i = 1; i <= n; i++) {
while(r.size() && r.front().s < i)
r.pop();
r.push(mp(i,i + dp[i] - 1));
ll z = r.front().f;
que.pb(mp(suf[z - i + z],mp((z - i + z), i)));
}
while(r.size())r.pop();
for(int i = 1; i <= n; i++) {
while(r.size() && r.front().s < i)
r.pop();
r.push(mp(i, i + dp2[i]));
ll z = r.front().f;
if(i == z)continue;
que.pb(mp(suf[z - i + z + 1], mp(z - (i - z - 1), i)));
}
}
ll comp(ll l1, ll r1, ll l2, ll r2) {
ll mn = __lg(min(r1 - l1 + 1, r2 - l2 + 1));
ll d = min(r1 - l1 + 1, r2 - l2 + 1);
if(a[mn][l1] == a[mn][l2]) {
ll z = (l1 + d - 1) - (1<<mn) + 1;
ll z2 = (l2 + d - 1) - (1<<mn) + 1;
if(a[mn][z] == a[mn][z2]) {
if(r1 - l1 + 1 <= r2 - l2 + 1)
return 2;
return 0;
}
return a[mn][z] < a[mn][z2];
}
return (a[mn][l1] < a[mn][l2]);
}
int main() {
speed;
cin >> b;
n = b.size();
sufmas();
manaker();
sort(que.begin(), que.end());
ll ans = 0;
for(auto u : que) {
ll L = 0, R = n - 1, l = -1, r = -1;
while(L <= R) {
ll m = (L + R) >> 1ll;
ll z = comp(u.s.f, u.s.s, x[m].s, n);
if(z == 2)
l = m;
if(z >= 1)
R = m - 1;
else
L = m + 1;
}
L = 0, R = n - 1, r = -1;
while(L <= R) {
ll m = (L + R) >> 1ll;
ll z = comp(u.s.f, u.s.s, x[m].s, n);
if(z == 2)
r = m;
if(z == 1)
R = m - 1;
else if( z == 2)
L = m + 1;
else
L = m + 1;
}
ans = max(ans, (r - l + 1) * (u.s.s - u.s.f + 1));
}
cout << ans;
}
