def ispali(s):
    for i in range(len(s)//2):
        if s[i] != s[-i-1]:
            return False
    return True

s = input()
n = len(s)
for i in range(n):
    if i == n-1 or ispali(s[i:]):
        res = s[:i]
        print(s + res[::-1])
        exit()