use itertools::Itertools;
use proconio::{input, marker::Chars};

fn main() {
    input! {
        mut s: Chars,
    }

    for i in (0..s.len()).rev() {
        if is_palindrome(&s) {
            break;
        }
        s.push(s[i]);
    }

    println!("{}", s.iter().join(""));
}

fn is_palindrome(s: &Vec<char>) -> bool {
    for i in 0..s.len() / 2 {
        if s[i] != s[s.len() - i - 1] {
            return false;
        }
    }
    true
}