#include<bits/stdc++.h>
using namespace std;
char s1[1000005], s2[1000005], s3[1000005];
int Next[1000005], cnt, len1, len2, len3, n, ss[1000005], st[1000005], top;
void getNext(char *p, int plen) {
	Next[0] = 0, Next[1] = 0;
	for(int i = 1;i <= plen;i ++) {
		int j = Next[i];
		while(j && p[i] != p[j]) {
			j = Next[j];
		}
		if(p[i] == p[j]) {
			Next[i + 1] = j + 1;
		}
		else Next[i + 1] = 0;
	}
}
void kmp(char *s, char *p) {
	int last = -1;
	int slen = strlen(s), plen = strlen(p);
	getNext(p, plen);
	int j = 0;
	for(int i = 0;i < plen;i ++) {
		while(j && p[i] != s[j]) {
			j = Next[j];
		}
		if(p[i] == s[j]) j ++;
		ss[i] = j; 
		st[++ top] = i;
		if(j >= slen) {
			top -= slen;
			j = ss[st[top]];
			last = i; 
		}
	} 
}
signed main() {
	cin >> s1;
	len1 = strlen(s1);
	if(len1 == 1) {
		cout << s1;
		return 0;
	} 
	if(len1 == 2) {
		if(s1[0] == s1[1]) {
			cout << s1;
		}
		else {
			cout << s1[0] << s1[1] << s1[0];
		}
		return 0;
	} 
	for(int i = len1;i >= 1;i --) {
		s2[len1 + i - 1] = s1[len1 - i];
	}
	for(int i = 0;i < len1;i ++) {
		s2[i] = s1[i];
	}
	len2 = len1 + len1;
	while(s2[len2 - 1 - 1] == s2[len2 - 1]) len2 --; 
	getNext(s2, len2);
	int border = len2 - Next[len2 - 1] - len1 - 2;
	cout << s1; 
	for(int i = border;i < len1;i ++) {
		cout << s2[len1 + i]; 
	} 
}