#include<iostream>

#include<algorithm>

#include<vector>

#include<stack>

#include<queue>

#include<map>

#include<set>

#include<cstdio>

#include<cstring>

#include<cmath>

#include<ctime>

#define fuck(x) cerr<<#x<<" = "<<x<<endl;

#define debug(a, x) cerr<<#a<<"["<<x<<"] = "<<a[x]<<endl;

#define ls (t<<1)

#define rs ((t<<1)|1)

using namespace std;

typedef long long ll;

typedef unsigned long long ull;

const int maxn = ;

const int maxm = ;

const int inf = 0x3f3f3f3f;

const ll Inf = ;

const int mod = ;

const double eps = 1e-;

const double pi = acos(-);

char s[maxn];

int len, Rank[maxn], sa[maxn], tlen, tmp[maxn];

bool compare_sa(int i, int j) {

    if (Rank[i] != Rank[j]) { return Rank[i] < Rank[j]; }

    //如果以i开始,长度为k的字符串的长度,已经超出了字符串尾,那么就赋值为-1

    //这是因为,在前面所有数据相同的情况下,字符串短的字典序小.

    int ri = i + tlen <= len ? Rank[i + tlen] : -inf;

    int rj = j + tlen <= len ? Rank[j + tlen] : -inf;

    return ri < rj;

}

void construct_sa() {

    //初始的RANK为字符的ASCII码

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

        sa[i] = i;

        Rank[i] = i < len ? s[i] : -inf;

    }

    for (tlen = ; tlen <= len; tlen *= ) {

        sort(sa, sa + len + , compare_sa);

        tmp[sa[]] = ;

        //全新版本的RANK,tmp用来计算新的rank

        //将字典序最小的后缀rank计为0

        //sa之中表示的后缀都是有序的,所以将下一个后缀与前一个后缀比较,如果大于前一个后缀,rank就比前一个加一.

        //否则就和前一个相等.

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

            tmp[sa[i]] = tmp[sa[i - ]] + (compare_sa(sa[i - ], sa[i]) ?  : );

        }

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

            Rank[i] = tmp[i];

        }

    }

}

int height[maxn];

void construct_lcp() {

//    for(int i=0;i<=n;i++){Rank[sa[i]]=i;}

    int h = ;

    height[] = ;

    for (int i = ; i < len; i++) {//i为后缀数组起始位置

        int j = sa[Rank[i] - ];//获取当前后缀的前一个后缀(排序后)

        if (h > )h--;

        for (; j + h < len && i + h < len; h++) {

            if (s[j + h] != s[i + h])break;

        }

        height[Rank[i]] = h;

    }

}

int st[maxn][];

void rmq_init() {

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

        st[i][] = height[i];

    }

    int l = ;

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

        for (int j = ; j + l /  <= len; j++) {

            st[j][i] = min(st[j][i - ], st[j + l / ][i - ]);

        }

        l <<= ;

    }

}

int ask_min(int i, int j) {

    int k = int(log(j - i + 1.0) / log(2.0));

    return min(st[i][k], st[j - ( << k) + ][k]);

}

int lcp(int a, int b)//此处参数是,原字符串下标

{

    a = Rank[a], b = Rank[b];

    if (a > b)

        swap(a, b);

    return ask_min(a + , b);

}

int solve(){

    int ans=,pos=;

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

        if(sa[i]==len/+){

            pos=i;

            break;

        }

    }

    int mn=inf;

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

        mn=min(height[i],mn);

        if(sa[i]==len/-mn){

            ans=max(mn,ans);

        }

    }

    mn=inf;

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

        mn=min(height[i],mn);

        if(sa[i-]==len/-mn){

            ans=max(mn,ans);

        }

    }

    return ans;

}

int main() {

//    ios::sync_with_stdio(false);

//    freopen("in.txt", "r", stdin);

    while (scanf("%s",s)!=EOF){

        len=strlen(s);

        s[len]='$';

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

            s[len*-i]=s[i];

        }

        len=len*+;

        height[len+]=;

        s[len]=;

        construct_sa();

        construct_lcp();

        int l=,r=len;

        int ans=solve();

        len/=;

        int tmps=len-ans;

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

            s[len+i]=s[len-ans-i-];

        }

        s[len+tmps]=;

        printf("%s\n",s);

    }

    return ;

}