#include <bits/stdc++.h>
using namespace std;
#define X first
#define Y second
#define mp make_pair
#define pb push_back
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <int, pii> pip;
typedef pair <pii, int> ppi;
typedef pair <ll, ll> pll;
const int INF=0x3f3f3f3f;
const int N=3e5+5;
const int LOG=20;
int n;
char s[N];
int suff[N], lcp[N];
int odd[N], even[N];
int rmq[LOG][N];
int ind[N], novi[N];
vector <int> vec[N];
int counter[30], count2[30];
vector <pii> v, upd;
int P[N], siz[N];
#define DEBUG 0
int cmp(int a, int b) {
return s[a]<s[b];
}
int cmp2(pii a, pii b) {
if (a.Y==b.Y) return a.X<b.X;
return a.Y>b.Y;
}
int name(int x) {
if (x==P[x]) return x;
P[x]=name(P[x]);
return P[x];
}
void mrg(int a, int b) {
a=name(a); b=name(b);
if (a==b) return;
P[a]=b;
siz[b]+=siz[a];
}
inline int modaj(int x) {
return x>=n ? x-n : x;
}
void build_suff() {
s[n]='$'; s[n+1]='\0'; n++;
for (int i=0; i<n; ++i) suff[i]=i;
sort(suff, suff+n, cmp);
ind[suff[0]]=0;
for (int i=1; i<n; ++i) ind[suff[i]]=ind[suff[i-1]]+(s[suff[i]]!=s[suff[i-1]]);
for (int j=1; j<n; j*=2) {
for (int i=0; i<n; ++i) vec[i].clear();
for (int i=0; i<n; ++i) {
suff[i]=modaj(suff[i]-j+n);
vec[ind[suff[i]]].pb(suff[i]);
}
int curr=0;
for (int i=0; i<n; ++i)
for (int x:vec[i])
suff[curr++]=x;
novi[suff[0]]=0;
for (int i=1; i<n; ++i) {
if (ind[suff[i-1]]==ind[suff[i]] && ind[modaj(suff[i-1]+j)]==ind[modaj(suff[i]+j)]) novi[suff[i]]=novi[suff[i-1]];
else novi[suff[i]]=novi[suff[i-1]]+1;
}
memcpy(ind, novi, sizeof(novi));
}
}
void build_lcp() {
int lc=0;
for (int i=0; i<n-1; ++i) {
int curr=ind[i];
int j=suff[curr-1];
while (s[i+lc]==s[j+lc]) lc++;
lcp[curr-1]=lc;
lc=max(lc-1, 0);
}
}
void solve() {
build_suff();
build_lcp();
#if DEBUG
for (int i=0; i<n; ++i) printf("%d ", suff[i]);
printf("\n");
for (int i=0; i<n; ++i) printf("%d ", lcp[i]);
printf("\n");
#endif // DEBUG
ll sol=0;
for (int i=0; i<n-1; ++i) counter[s[i]-'a']++;
for (int i=0; i<26; ++i) sol=max(sol, (ll)counter[i]);
odd[0]=1;
int cent=0, r=0;
for (int i=1; i<n-1; ++i) {
odd[i]=(i>r) ? 1 : min(r-i+1, odd[cent-(i-cent)]);
while (i-odd[i]>=0 && i+odd[i]<n && s[i-odd[i]]==s[i+odd[i]]) {
v.pb(mp(i-odd[i], odd[i]*2+1));
odd[i]++;
}
if (i+odd[i]-1>r) cent=i, r=i+odd[i]-1;
}
even[0]=0;
cent=0, r=0;
for (int i=1; i<n-1; ++i) {
even[i]=(i>r) ? 0 : min(r-i+1, even[cent-(i-cent)-1]);
while (i-even[i]-1>=0 && i+even[i]<n && s[i-even[i]-1]==s[i+even[i]]) {
v.pb(mp(i-even[i]-1, even[i]*2+2));
even[i]++;
}
if (i+even[i]-1>r) cent=i, r=i+even[i]-1;
}
for (int i=1; i<n-1; ++i) upd.pb(mp(i, lcp[i]));
sort(upd.begin(), upd.end(), cmp2);
sort(v.begin(), v.end(), cmp2);
for (int i=0; i<n; ++i) P[i]=i, siz[i]=1;
int j=0;
for (int i=0; i<v.size(); ++i) {
while (j<upd.size() && upd[j].Y>=v[i].Y) {
// printf("update %d i %d\n", suff[upd[j].X], suff[upd[j].X+1]);
mrg(suff[upd[j].X], suff[upd[j].X+1]);
j++;
}
// printf("pos: %d, dulj: %d\n", v[i].X, v[i].Y);
int x=name(v[i].X);
sol=max(sol, (ll)v[i].Y*siz[x]);
}
printf("%lld\n", sol);
}
void load() {
scanf("%s", s);
n=strlen(s);
}
int main() {
load();
solve();
return 0;
}
