#include<cstdio>
#include<cstring>
#include<iostream>
using namespace std;
const int N=3e5+5;
typedef long long ll;
int n,p[N<<2],f[N][21],log2[N];
char s[N],S[N<<1];
int c[N],h[N],sa[N],tsa[N],rank[N],trank[N];
ll ans;
void DA(int maxx=256){int p;for(int i=1;i<=maxx;i++) c[i]=0;for(int i=1;i<=n;i++) c[rank[i]=s[i]]++;for(int i=1;i<=maxx;i++) c[i]+=c[i-1];for(int i=n;i;i--) sa[c[rank[i]]--]=i;trank[sa[1]]=p=1;for(int i=2;i<=n;i++){if(rank[sa[i]]!=rank[sa[i-1]]) p++;trank[sa[i]]=p;}for(int i=1;i<=n;i++) rank[i]=trank[i];for(int k=1;p<n;k<<=1,maxx=p){p=0;for(int i=n-k+1;i<=n;i++) tsa[++p]=i;for(int i=1;i<=n;i++) if(sa[i]>k) tsa[++p]=sa[i]-k;for(int i=1;i<=maxx;i++) c[i]=0;for(int i=1;i<=n;i++) trank[i]=rank[tsa[i]];for(int i=1;i<=n;i++) c[trank[i]]++;for(int i=1;i<=maxx;i++) c[i]+=c[i-1];for(int i=n;i;i--) sa[c[trank[i]]--]=tsa[i];trank[sa[1]]=p=1;for(int i=2;i<=n;i++){if(rank[sa[i]]!=rank[sa[i-1]]||rank[sa[i]+k]!=rank[sa[i-1]+k]) p++;trank[sa[i]]=p;}for(int i=1;i<=n;i++) rank[i]=trank[i];}for(int i=1,k=0;i<=n;i++){int j=sa[rank[i]-1];while(s[i+k]==s[j+k]) k++;h[rank[i]]=k;if(k>0) k--;}
}
void RMQ(){for(int i=1;i<=n;i++) f[i][0]=h[i];for(int i=2;i<=n;i++) log2[i]=log2[i>>1]+1;for(int j=1;j<=log2[n];j++){for(int i=1;i+(1<<j)-1<=n;i++){f[i][j]=min(f[i][j-1],f[i+(1<<j-1)][j-1]);}}
}
int query(int l,int r){if(l>r) return 0;//WA*1int k=log2[r-l+1];return min(f[l][k],f[r-(1<<k)+1][k]);
}
ll solve(int l,int r){if(l>r) return 0;//WA*1int pos=rank[l],L=0,R=pos,up=pos,dn=pos;while(L+1<R){//WA*1int mid=L+R>>1;if(query(mid+1,pos)>=r-l+1) R=mid,up=mid;else L=mid;}L=pos,R=n+1;//WA*1while(L+1<R){int mid=L+R>>1;if(query(pos+1,mid)>=r-l+1) L=mid,dn=mid;else R=mid;}return 1LL*(dn-up+1)*(r-l+1);
}
int opl,opr,lal=-1,rar=-1;
void find(char c,int pos,int d){//WA*1bool f=0;if(c!='#') pos++;else f=1;pos/=2;d/=2;opr=pos+d;pos-=d;if(f) pos++;opl=pos;
}
void manacher(){int l=-1;for(int i=1;i<=n;i++) S[++l]='#',S[++l]=s[i];S[++l]='#';int id=0,mx=-1;ll t;for(int i=1;i<l;i++){if(id+mx>i) p[i]=min(p[id*2-i],id+mx-i);while(i-p[i]-1>=0&&i+p[i]+1<=l&&S[i-p[i]-1]==S[i+p[i]+1]){p[i]++;if(id+mx<i+p[i]){find(S[i],i,p[i]);if(opl==lal&&opr==rar) continue;lal=opl;rar=opr;//TLE*1t=solve(opl,opr);if(ans<t) ans=t;}             }if(id+mx<i+p[i]) id=i,mx=p[i];}
}
int main(){scanf("%s",s+1);n=strlen(s+1);DA();RMQ();//WA*1
    manacher();cout<<ans;return 0;
}