S = input()

def check(s):
    n = len(s) // 2
    flag = True
    for i in range(n):
        if s[i] != s[-i-1] : flag = False; break
    return flag

if check(S) : exit(print(S))

N = len(S)

for i in range(1, N):
    if check(S[i:]):
        ans = S
        for j in range(i-1, -1, -1):
            ans = ans + S[j]
        break
print(ans)