#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define N 300010
#define ii pair<int,int>
#define fs first
#define sc second
#define ld double
int n;
string s;
ll ans=0;
/*struct BIT
{
int bit[N]={};
void init()
{
memset(bit,0,sizeof(bit));
}
void update(int u,int val)
{
for(;u<=n;u+=u&(-u))
bit[u]+=val;
}
int get(int u)
{
int res=0;
for(;u>0;u-=u&(-u))
res+=bit[u];
return res;
}
}BIT;*/
struct DoubleHash
{
vector<ll> H1, H2, p1, p2;
ll base1 = 311, base2 = 313, mod1 = 1e9 + 8277, mod2 = 1e9 + 9277;
void init(string s, int n)
{
p1.resize(n + 1, 1), p2.resize(n + 1, 1), H1.resize(n + 1, 0), H2.resize(n + 1, 0);
for (int i = 1; i <= n; i++)
{
p1[i] = p1[i - 1] * base1 % mod1;
p2[i] = p2[i - 1] * base2 % mod2;
H1[i] = (H1[i - 1] * base1 + s[i]-'A'+1) % mod1;
H2[i] = (H2[i - 1] * base2 + s[i]-'A'+1) % mod2;
}
}
ll getHash(int u, int v)
{
ll t1 = (H1[v] - H1[u - 1] * p1[v - u + 1] + mod1 * mod1) % mod1;
ll t2 = (H2[v] - H2[u - 1] * p2[v - u + 1] + mod2 * mod2) % mod2;
return t1 * 1000000000 + t2;
}
}xuoi,nguoc;
bool check_palin(int l,int r)
{
return (xuoi.getHash(l,r)==nguoc.getHash(n-r+1,n-l+1));
}
struct SA
{
int sa[N]={},pos[N]={},lcp[N]={},cnt[N]={},tmp[N]={};
bool SS(int u,int v,int k)
{
if(pos[u]!=pos[v])
return pos[u]<pos[v];
if(u+k<=n&&v+k<=n)
return pos[u+k]<pos[v+k];
return(u>v);
}
void countsort(int k)
{
fill(cnt,cnt+1+max(256,n),0);
for(int i=1;i<=n;i++)
cnt[(i+k<=n ? pos[i+k] : 0)]++;
for(int i=1;i<=max(256,n);i++)
cnt[i]+=cnt[i-1];
for(int i=n;i>=1;i--)
tmp[cnt[(sa[i]+k<=n ? pos[sa[i]+k] : 0)]--]=sa[i];
for(int i=1;i<=n;i++)
sa[i]=tmp[i];
}
void make_SA()
{
for(int i=1;i<=n;i++)
{
sa[i]=i;
pos[i]=s[i];
}
for(int k=1;k<=n;k<<=1)
{
countsort(k);
countsort(0);
tmp[sa[1]]=1;
for(int i=2;i<=n;i++)
tmp[sa[i]]=tmp[sa[i-1]]+SS(sa[i-1],sa[i],k);
for(int i=1;i<=n;i++)
pos[i]=tmp[i];
}
}
void make_lcp()
{
for(int i=1;i<=n;i++)
pos[sa[i]]=i;
int k=0;
for(int i=1;i<=n;i++)
{
if(pos[i]==n)
{
lcp[pos[i]]=0;
continue;
}
int j=sa[pos[i]+1];
while(i+k<=n&&j+k<=n&&s[i+k]==s[j+k])
k++;
lcp[pos[i]]=k;
k-=(k>0);
}
}
vector<int>gop[N];
void build()
{
for(int i=1;i<n;i++)
gop[lcp[i]].pb(i);
}
}SA;
struct DSU
{
int dem=0,lab[N]={},sz[N]={};
void init()
{
dem=0;
memset(lab,-1,sizeof(lab));
memset(sz,0,sizeof(sz));
}
int root(int u)
{
if(lab[u]<0)
return u;
return(lab[u]=root(lab[u]));
}
void update(int u,int v)
{
if((u=root(u))==(v=root(v)))
return;
if(lab[u]>lab[v])
swap(u,v);
lab[u]+=lab[v];
lab[v]=u;
sz[u]+=sz[v];
dem=max(dem,sz[u]);
}
void them(int u)
{
u=root(u);
dem=max(dem,++sz[u]);
}
}DSU;
struct le
{
vector<int>lis[N];
void solve()
{
//BIT.init();
DSU.init();
for(int i=1;i<=n;i++)
{
int val=0,l=1,r=min(i,n-i+1);
while(l<=r)
{
int mid=(l+r)/2;
if(check_palin(i-mid+1,i+mid-1))
{
val=mid;
l=mid+1;
}else
r=mid-1;
}
lis[val].pb(SA.pos[i]);
}
for(int length=n;length>=1;length--)
{
for(auto u:lis[length])
DSU.them(u);
for(auto u:SA.gop[length])
DSU.update(u,u+1);
ans=max(ans,1ll*DSU.dem*(length*2-1));
}
}
}le;
struct chan
{
vector<int>lis[N];
void solve()
{
//BIT.init();
DSU.init();
for(int i=1;i<=n;i++)
{
int val=0,l=1,r=min(i-1,n-i+1);
while(l<=r)
{
int mid=(l+r)/2;
if(check_palin(i-mid,i+mid-1))
{
val=mid;
l=mid+1;
}else
r=mid-1;
}
lis[val].pb(SA.pos[i]);
}
for(int length=n;length>=1;length--)
{
for(auto u:lis[length])
DSU.them(u);
for(auto u:SA.gop[length])
DSU.update(u,u+1);
ans=max(ans,1ll*DSU.dem*(length*2));
}
}
}chan;
int main()
{
#ifdef SKY
freopen("A.inp","r",stdin);
freopen("A.out","w",stdout);
#endif // SKY
ios::sync_with_stdio(0);
cin.tie(NULL);
cout.tie(NULL);
cin>>s;
n=s.size();
s=" "+s;
for(int i=1;i*2<=n;i++)
swap(s[i],s[n-i+1]);
nguoc.init(s,n);
for(int i=1;i*2<=n;i++)
swap(s[i],s[n-i+1]);
xuoi.init(s,n);
SA.make_SA();
SA.make_lcp();
SA.build();
//cout<<s<<endl;
// for(int i=1;i<=n;i++)cout<<SA.sa[i]<<" "<<SA.lcp[i]<<endl;
le.solve();
chan.solve();
cout<<ans;
return 0;
}
