#include<cstdio>

#include<cstring>

#include<algorithm>

using namespace std;

#define N 100001

char ss[N];

int s[N];

int L1[N],L2[N];

struct TREE

{

    int tot,last;

    int len[N],tr[N][],fail[N];

    int p,c,np,t;

    int n;

    void clear()

    {

        tot=; last=;

        memset(tr[],,sizeof(tr[]));

        memset(tr[],,sizeof(tr[]));

        fail[]=; fail[]=;

        len[]=; len[]=-;

        s[]=-; n=;

    }

    int newnode(int f)

    {

        tot++;

        memset(tr[tot],,sizeof(tr[tot]));

        fail[tot]=;

        len[tot]=len[f]+;

        return tot;

    }

    int extend(int c)

    {

        s[++n]=c;

        p=last;

        while(s[n--len[p]]!=c) p=fail[p];

        if(!tr[p][c])

        {

            np=newnode(p);

            t=fail[p];

            while(s[n--len[t]]!=c) t=fail[t];

            fail[np]=tr[t][c];

            tr[p][c]=np;

        }

        else np=tr[p][c];

        return len[last=np];

    }

}tree;

int main()

{

    scanf("%s",ss+);

    int n=strlen(ss+);

    tree.clear();

    for(int i=;i<=n;++i)

        L1[i]=tree.extend(ss[i]-'a');

    tree.clear();

    for(int i=n;i;--i)

        L2[i]=tree.extend(ss[i]-'a');

    int ans=;

    for(int i=;i<n;++i) ans=max(ans,L1[i]+L2[i+]);

    printf("%d",ans);

}