#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("O2")
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
typedef long long ll;
const int mod[2] = {int(1e9 + 7), int(1e9 + 9)};
const int base[2] = {int(727), int(1e6 + 1)};
const int N = 1e4 + 10;
string s;
int n, base_pwr[2][N], inv[2];
int pwr(int a, int b, int id){
if (b < 0) return 0;
if (b == 0) return 1;
int val = pwr(a, b / 2, id);
val = (1ll * val * val) % mod[id];
if (b % 2) val = (1ll * val * a) % mod[id];
return val;
}
int main(){
for (int j = 0; j < 2; j ++){
base_pwr[j][0] = 1;
inv[j] = pwr(base[j], mod[j] - 2, j);
for (int i = 1; i < N; i ++)
base_pwr[j][i] = (1ll * base_pwr[j][i - 1] * base[j]) % mod[j];
}
cin >> s;
n = s.size();
int ans = 0;
for (int len = 1; len <= n; len ++){
int hsh0 = 0, hsh = 0;
unordered_map<int, int> cnt;
int mx_occur = 0;
for (int i = 0; i < len; i ++){
hsh = (1ll * hsh * base[0] + s[i]) % mod[0];
hsh0 = (1ll * hsh0 + 1ll * base_pwr[0][i] * s[i]) % mod[0];
}
if (hsh == hsh0){
cnt[hsh]++;
mx_occur = 1;
}
for (int i = 1; i + len - 1 < n; i ++){
hsh = (1ll * hsh - 1ll * base_pwr[0][len - 1] * s[i - 1]) % mod[0];
hsh = (1ll * hsh * base[0] + s[i + len - 1]) % mod[0];
hsh = (hsh + mod[0]) % mod[0];
hsh0 = (hsh0 - s[i - 1] + mod[0]) % mod[0];
hsh0 = (1ll * hsh0 * inv[0]) % mod[0];
hsh0 = (1ll * hsh0 + 1ll * base_pwr[0][len - 1] * s[i + len - 1]) % mod[0];
if (hsh == hsh0 and hsh == hsh0){
cnt[hsh]++;
mx_occur = max(mx_occur, cnt[hsh]);
}
}
ans = max(ans, len * mx_occur);
}
cout << ans << endl;
}
