#include<bits/stdc++.h>

#define LL long long

#define fi first

#define se second

#define mk make_pair

#define PII pair<int, int>

#define PLI pair<LL, int>

#define ull unsigned long long

using namespace std;

const int N =  + ;

const int inf = 0x3f3f3f3f;

const LL INF = 0x3f3f3f3f3f3f3f3f;

const int mod = 1e9 + ;

const double eps = 1e-;

const int base = ;

int n, m, p[N<<];

char s[N<<];

struct SuffixAutomaton {

    int last, cur, cnt, ch[N<<][], id[N<<], fa[N<<], dis[N<<], sz[N<<], c[N];

    int f[N<<][], pos[N<<];

    SuffixAutomaton() {cur = cnt = ;}

    void init() {

        for(int i = ; i <= cnt; i++) {

            memset(ch[i], , sizeof(ch[i]));

            sz[i] = c[i] = dis[i] = fa[i] = ;

        }

        cur = cnt = ;

    }

    void extend(int c, int id) {

        last = cur; cur = ++cnt;

        int p = last; dis[cur] = id;

        for(; p && !ch[p][c]; p = fa[p]) ch[p][c] = cur;

        if(!p) fa[cur] = ;

        else {

            int q = ch[p][c];

            if(dis[q] == dis[p]+) fa[cur] = q;

            else {

                int nt = ++cnt; dis[nt] = dis[p]+;

                memcpy(ch[nt], ch[q], sizeof(ch[q]));

                fa[nt] = fa[q]; fa[q] = fa[cur] = nt;

                for(; ch[p][c]==q; p=fa[p]) ch[p][c] = nt;

            }

        }

        sz[cur] = ;

    }

    void getSize(int n) {

        for(int i = ; i <= cnt; i++) c[dis[i]]++;

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

        for(int i = cnt; i >= ; i--) id[c[dis[i]]--] = i;

        for(int i = cnt; i >= ; i--) {

            int p = id[i];

            sz[fa[p]] += sz[p];

        }

    }

    LL query(int p, int len) {

        for(int j = ; j >= ; j--) {

            if(f[p][j] && dis[f[p][j]] >= len) p = f[p][j];

        }

        return 1ll*len*sz[p];

    }

    void solve() {

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

            p = ch[p][s[i]-'a'], pos[i] = p;

        for(int i = ; i <= cnt; i++) f[i][] = fa[i];

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

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

                f[i][j] = f[f[i][j-]][j-];

        LL ans = ;

        s[] = '-', s[n+] = '+';

        int mx = , id = ;

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

            if(mx > i) p[i] = min(mx-i, p[*id-i]);

            else p[i]=, ans = max(ans, query(pos[i], ));

            while(s[i+p[i]]==s[i-p[i]]) p[i]++, ans = max(ans, query(pos[i+p[i]-], *p[i]-));

            if(i+p[i]>mx) mx = i+p[i], id = i;

        }

        mx = , id = ;

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

            if(mx > i) p[i] = min(mx-i, p[*id-i]);

            else p[i] = ;

            while(s[i+p[i]+]==s[i-p[i]]) p[i]++, ans = max(ans, query(pos[i+p[i]], *p[i]));

            if(i+p[i]>mx) mx = i+p[i], id = i;

        }

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

    }

} sam;

int main() {

    scanf("%s", s + );

    n = strlen(s + );

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

        sam.extend(s[i]-'a', i);

    sam.getSize(n);

    sam.solve();

    return ;

}

/*

*/