#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <string>
#include <cmath>
#include <cstdio>
#include <iomanip>
#include <fstream>
#include <cassert>
#include <cstring>
#include <unordered_set>
#include <unordered_map>
#include <numeric>
#include <ctime>
#include <bitset>
#include <complex>
#include <chrono>
#include <random>
#include <functional>
using namespace std;
const int INF = 1e9 + 239;
const int ALP = 26;
namespace Hash {
int n;
string s;
int req(int i, int j, int len) {
while (len) {
if (i < 0 || j >= n) return 0;
if (s[i] != s[j]) return 0;
i--;
j++;
len--;
}
return 1;
}
void init(string s_) {
s = s_;
n = (int)s.size();
}
}
namespace SuffixArray {
int n;
string s;
vector<int> sa;
vector<int> wr;
int lcp(int i, int j) {
//TODO
int ans = 0;
while (i < n && j < n) {
if (s[i] != s[j]) {
return ans;
}
ans++;
i++;
j++;
}
return ans;
}
int eq(int i, int j, int len) {
return lcp(i, j) >= len;
}
int cmp(int i, int j) {
int sk = lcp(i, j);
i += sk;
j += sk;
if (i == n && j == n) {
return 0;
}
if (i == n || s[i] < s[j]) {
return -1;
} else {
return 1;
}
}
void init(string s_) {
s = s_;
n = (int)s.size();
for (int i = 0; i < n; i++) {
sa.push_back(i);
}
sort(sa.begin(), sa.end(), [&](int i, int j) {
return cmp(i, j) == -1;
});
wr.resize(n);
for (int i = 0; i < n; i++) {
wr[sa[i]] = i;
}
}
}
void solve(vector<int> v, int ml, int add, int &ans) {
int n = (int)v.size();
for (int i = 0; i < n; i++) {
int mn = INF;
for (int j = i; j < n; j++) {
mn = min(mn, v[j]);
ans = max(ans, (j - i + 2) * (mn * ml + add));
}
}
}
int cnt[ALP];
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
string s;
cin >> s;
int n = (int)s.size();
Hash::init(s);
SuffixArray::init(s);
int ans = 0;
auto cmp = [&](pair<int, int> X, pair<int, int> Y) {
int i1, len1, i2, len2;
tie(i1, len1) = X;
tie(i2, len2) = Y;
int sk = SuffixArray::lcp(i1, i2);
if (sk >= len1 || sk >= len2) {
return len1 < len2;
}
i1 += sk;
i2 += sk;
return (i1 == n || s[i1] < s[i2]);
};
//single
{
for (int i = 0; i < n; i++) {
cnt[s[i] - 'a']++;
ans = max(ans, cnt[s[i] - 'a']);
}
}
//even
{
vector<pair<int, int>> ip;
for (int i = 0; i < n; i++) {
int mx = -1;
int l = -1;
int r = n +1;
while (r - l > 1) {
int mid = (r + l) / 2;
if (mid <= i && mid + i <= n && Hash::req(i - 1, i, mid)) {
l = mid;
} else {
r = mid;
}
}
mx = l;
ans = max(ans, 2 * mx);
if (mx != -1) {
ip.push_back({i, mx});
}
}
sort(ip.begin(), ip.end(), cmp);
vector<int> val;
for (int i = 0; i + 1 < (int)ip.size(); i++) {
val.push_back(min({ip[i].second, ip[i + 1].second, SuffixArray::lcp(ip[i].first, ip[i + 1].first)}));
}
solve(val, 2, 0, ans);
}
//odd
{
vector<pair<int, int>> ip;
for (int i = 0; i < n; i++) {
int mx = -1;
int l = -1;
int r = n +1;
while (r - l > 1) {
int mid = (r + l) / 2;
if (mid <= i && mid + i + 1 <= n && Hash::req(i - 1, i + 1, mid)) {
l = mid;
} else {
r = mid;
}
}
mx = l;
ans = max(ans, 2 * mx + 1);
if (mx != -1) {
ip.push_back({i, mx + 1});
}
}
sort(ip.begin(), ip.end(), cmp);
vector<int> val;
for (int i = 0; i + 1 < (int)ip.size(); i++) {
val.push_back(min({ip[i].second, ip[i + 1].second, SuffixArray::lcp(ip[i].first, ip[i + 1].first)}));
}
solve(val, 2, -1, ans);
}
cout << ans << endl;
}
