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

const int MAX_N = 300010, inf = 1e9;

int w[MAX_N], man[MAX_N], vl[MAX_N], vr[MAX_N], n, tmp[MAX_N];

void getv(int v[]) {
    int m = 0;
    for (int i = 0;i < n;++i)
        tmp[m++] = w[i], tmp[m++] = -1;

    // manacher
    for (int l = -1, r = -1, i = 0;i < m;++i) {
        man[i] = 1;
        if (r >= i) man[i] = min(r - i + 1, man[l + r - i]);
        while (i + man[i] < m && i - man[i] >= 0 && tmp[i-man[i]] == tmp[i+man[i]])
            ++man[i];
        if (i + man[i] - 1 >= r)
            l = i - man[i] + 1, r = i + man[i] - 1;
    }

    for (int i = 0;i < m;++i) {
        int l = (i - man[i] + 2) / 2, wid = (i&1) ? man[i]/2*2 : (man[i]-1)/2*2+1;
        v[l] = max(v[l], wid);
    }
    for (int i = 1;i < n;++i)
        v[i] = max(v[i], v[i-1] - 1);
}

int32_t main() {
    ios_base::sync_with_stdio(0), cin.tie(0);
    while (cin >> w[n]) ++n;

    getv(vl);
    reverse(w, w+n);
    getv(vr);
    reverse(w, w+n);
    reverse(vr, vr+n);

    int res = 0, beg = 0;
    for (int i = 1;i < n;++i) {
        res = max(res, vl[i] + vr[i-1]);
        if (res == vl[i] + vr[i-1]) {
            beg = i - vr[i-1];
        }
    }

    for (int i = 0;i < res;++i)
        cout << w[i + beg] << " \n"[i+1==res];
}