PALINY

#include <bits/stdc++.h>
using namespace std;

#define int long long

const int N = 100005;
const int base = 311;
const int mod = 1e9 + 7;

int p[N], l[N], r[N];
int f[N];

int getl(int u, int k) {
    return (l[u] - l[u - k] * p[k] + mod * mod) % mod;
}

int getr(int u, int k) {
    return (r[u] - r[u + k] * p[k] + mod * mod) % mod;
}

signed main() {
    int n; cin >> n;
    string t; cin >> t;

    string s = "@#";
    for (size_t i = 0; i < t.size(); i++) {
        s += t[i]; s += '#';
    }
    s += '$';
    n = s.size();

    p[0] = 1;
    for (int i = 1; i < n; i++) {
        p[i] = (p[i - 1] * base) % mod;
    }

    l[0] = s[0] - 'a' + 1;
    for (int i = 1; i < n; i++) {
        l[i] = (l[i - 1] * base + s[i] - 'a' + 1) % mod;
    }

    r[n - 1] = s[n - 1] - 'a' + 1;
    for (int i = n - 2; i >= 0; i--) {
        r[i] = (r[i + 1] * base + s[i] - 'a' + 1) % mod;
    }

    int ans = 1;
    for (int i = 1; i < n - 1; i++) {
        int l = 1, r = min(i, n - i - 1);
        while (l <= r) {
            int m = (l + r) / 2;
            if (getl(i, m) == getr(i, m)) {
                f[i] = m;
                l = m + 1;
            }
            else r = m - 1;
        }
        ans = max(ans, f[i]);
    }
    cout << ans << '\n';

    for (size_t i = 0; i < s.size(); i++) cout << setw(3) << i; cout << '\n';
    for (size_t i = 0; i < s.size(); i++) cout << setw(3) << s[i]; cout << '\n';
    for (size_t i = 0; i < s.size(); i++) cout << setw(3) << f[i]; cout << '\n';
}