#include<bits/stdc++.h>
using namespace std;
#define int long long
#define ii pair<int, int>
#define iii pair<ii, int>
#define mp make_pair
#define eb emplace_back
#define vi vector<int>
#define vii vector<ii>
#define viii vector<iii>
#define fi first
#define se second
#define xx fi.fi
#define yy fi.se
#define zz se
const int max_rank = 300005;
int n, even[max_rank], odd[max_rank], par[max_rank], w[max_rank], ans, mxw, cnt[max_rank];
int prev_idx[max_rank], idx[max_rank], prev_sa[max_rank], sa[max_rank], bucket[max_rank], lcp[max_rank];
string s;
int root(int x)
{
return par[x]<0? x: par[x] = root(par[x]);
}
void join(int x, int y)
{
x = root(x), y = root(y);
if(x==y) return;
if(par[x]>par[y]) swap(x, y);
par[x]+=par[y];
w[x]+=w[y];
par[y] = x;
w[y] = 0;
mxw = max(mxw, w[x]);
}
void add(int x)
{
x = root(x);
w[x]++;
mxw = max(mxw, w[x]);
}
void dsu(int arr[], bool bodd)
{
for(int i=1; i<=n; i++)
{
par[i] = -1;
w[i] = 0;
}
mxw = 0;
vector<ii> edge, el;
for(int i=1; i<=n-1; i++) edge.eb(lcp[i], i);
for(int i=1; i<=n; i++) el.eb(arr[sa[i]], i);
sort(begin(edge), end(edge));
sort(begin(el), end(el));
int edge_ptr = edge.size(), el_ptr = el.size();
for(int len = n; len>=1; len--)
{
while(el_ptr and el[el_ptr-1].fi>=len)
{
add(el[el_ptr-1].se);
el_ptr--;
}
while(edge_ptr and edge[edge_ptr-1].fi>=len)
{
join(edge[edge_ptr-1].se, edge[edge_ptr-1].se+1); // dit me nham thanh .fi moi cay chu
edge_ptr--;
}
ans = max(ans, mxw*(2*len-bodd));
}
}
signed main()
{
// freopen(".inp", "r", stdin);
// freopen(".out", "w", stdout);
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin>>s; n = s.length();
s = '$'+s+'$'; n++;
for(int len = 1; len<=(n<<1); len<<=1) // prev_sa: last suffix array, prev_idx: last rank, sa: idx suffix array, idx: idx rank
{
for(int i=1; i<max_rank; i++) cnt[i] = 0;
if(len==1)
{
for(int i=1; i<=n; i++) cnt[s[i]]++;
for(int i=1; i<max_rank; i++) cnt[i]+=cnt[i-1];
for(int i=1; i<=n; i++) sa[cnt[s[i]]--] = i;
for(int i=1; i<=n; i++) idx[sa[i]] = idx[sa[i-1]]+(s[sa[i]]>s[sa[i-1]]);
}
else
{
int hlf = len>>1;
for(int i=1; i<=n; i++) prev_idx[i] = idx[i], prev_sa[i] = sa[i];
for(int i=1; i<=n; i++) bucket[i] = prev_sa[i]-hlf<1? prev_sa[i]-hlf+n: prev_sa[i]-hlf;
for(int i=1; i<=n; i++) cnt[prev_idx[bucket[i]]]++;
for(int i=1; i<max_rank; i++) cnt[i]+=cnt[i-1];
for(int i=n; i>=1; i--) sa[cnt[prev_idx[bucket[i]]]--] = bucket[i];
for(int i=1; i<=n; i++)
{
if(i==1) idx[sa[i]] = 1;
else if(prev_idx[sa[i]]==prev_idx[sa[i-1]]
and prev_idx[(sa[i]+hlf-1)%n+1]==prev_idx[(sa[i-1]+hlf-1)%n+1]) idx[sa[i]] = idx[sa[i-1]];
else idx[sa[i]] = idx[sa[i-1]]+1;
}
}
}
int curl = 0;
for(int i=1; i<=n; i++)
{
if(idx[i]==n)
{
lcp[idx[i]] = 0;
continue;
}
int j = sa[idx[i]+1];
while(s[i+curl]==s[j+curl])
{
curl++;
}
lcp[idx[i]] = curl;
if(curl) curl--;
}
int l = 0, r = 0;
for(int i=1; i<=n; i++)
{
if(l<=i and i<=r)
{
odd[i] = min(odd[l+r-i], r-i+1);
}
while(i-odd[i]>=1 and i+odd[i]<=n and s[i-odd[i]]==s[i+odd[i]])
{
odd[i]++;
}
if(odd[i] and r<i+odd[i]-1)
{
r = i+odd[i]-1;
l = i-odd[i]+1;
}
}
l = 0, r = 0;
for(int i=2; i<=n; i++)
{
if(l<=i-1 and i<=r)
{
even[i] = min(even[l+r-i+1], r-i+1); // luc dau quen min o cho nay, toang vai. Nho lan sau phai co!.
}
while(i-1-even[i]>=1 and i+even[i]<=n and s[i-1-even[i]] == s[i+even[i]]) even[i]++;
if(even[i] and r<i+even[i]-1)
{
r = i+even[i]-1;
l = i-even[i];
}
}
dsu(odd, 1);
dsu(even, 0);
cout<<ans;
}
