#include<bits/stdc++.h>

using namespace std;

const int N = 3e5 + ;

int n, len, pos, mx;

long long ans;

int c[N << ], a[N << ], p[N << ], fa[N << ][], f[N << ], Pos[N];

char s[N], S[N << ];

namespace SAM

{

    struct node {

        int val, par;

        int ch[];

    } t[N << ];

    int sz = , root = , last = ;

    int nw(int _)

    {

        t[++sz].val = _;

        return sz;

    }

    void extend(int c)

    {

        int p = last, np = nw(t[p].val + );

        while(p && !t[p].ch[c]) t[p].ch[c] = np, p = t[p].par;

        if(!p) t[np].par = root;

        else

        {

            int q = t[p].ch[c];

            if(t[q].val == t[p].val + ) t[np].par = q;

            else

            {

                int nq = nw(t[p].val + );

                memcpy(t[nq].ch, t[q].ch, sizeof(t[q].ch));

                t[nq].par = t[q].par;

                t[q].par = t[np].par = nq;

                while(p && t[p].ch[c] == q) t[p].ch[c] = nq, p = t[p].par;

            }

        }

        last = np;

        Pos[t[np].val] = np;

        f[np] = ;

    }

    int query(int l, int r)

    {

        int len = r - l + , now = Pos[r];

        for(int i = ; i >= ; --i) if(t[fa[now][i]].val >= len) now = fa[now][i];

        return f[now];

    }

} using namespace SAM;

int main()

{

    scanf("%s", s + );

    n = strlen(s + );

    for(int i = ; i <= n; ++i) extend(s[i] - 'a');

    for(int i = ; i <= sz; ++i) ++c[t[i].val];

    for(int i = ; i <= sz; ++i) c[i] += c[i - ];

    for(int i = ; i <= sz; ++i) a[c[t[i].val]--] = i;

    for(int i = sz; i; --i) f[t[a[i]].par] += f[a[i]];

    for(int i = ; i <= sz; ++i) fa[i][] = t[i].par;

    for(int j = ; j <= ; ++j)

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

            fa[i][j] = fa[fa[i][j - ]][j - ]; 

    S[] = '-';

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

    {

        S[++len] = '#';

        S[++len] = s[i];

    }

    S[++len] = '#';

    S[++len] = '+';

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

    {

        if(i < mx) p[i] = min(mx - i, p[ * pos - i]);

        while(S[i - p[i]] == S[i + p[i]])

        {

            ans = max(ans, 1LL * p[i] * query((i - p[i] + ) >> , (i + p[i]) >> ));

            ++p[i];

        }

        if(i + p[i] > mx)

        {

            pos = i;

            mx = i + p[i];

        }

    }

    printf("%lld\n", ans);

    return ;

}