#include <bits/stdc++.h>
using namespace std;
#define int long long
int const mod=1e9+7;
int const base=727;
int const N=1e4+5;
string s;
int n;
int pre[N],suf[N];
int pw[N];
int hash_pre(int l,int r){
l--;
return ((pre[r]-((pre[l]*pw[r-l])%mod))+mod)%mod;
}
int hash_suf(int l,int r){
r++;
return ((suf[l]-((suf[r]*pw[r-l])%mod))+mod)%mod;
}
void make_hash(){
pw[0]=1;
for(int i=1;i<=n;i++)
pw[i]=(pw[i-1]*base)%mod;
int hsh=0;
for (int i = 0; i < n; ++i)
{
hsh=(hsh*base)%mod;
hsh=(hsh+s[i])%mod;
pre[i+1]=hsh;
}
hsh=0;
for(int i=n-1;i>=0;i--){
hsh=(hsh*base)%mod;
hsh=(hsh+s[i]);
suf[i+1]=hsh;
}
}
signed main(){
cin>>s;
n=s.length();
make_hash();
unordered_map<int,int> cnt;
int h=0;
for(int l=1;l<=n;l++)
for(int r=l;r<=n;r++){
h=hash_pre(l,r);
if(h==hash_suf(l,r))
cnt[h]+=(r-l)+1;
}
int maxx=0;
for(auto p:cnt)
maxx=max(maxx,p.second);
cout<<maxx<<endl;
return 0;
}
