def f(s):
    n=len(s)
    l=0
    r=n-1
    while r-l>=1:
        if s[l]!=s[r]:
            return False
        l+=1
        r-=1
    return True
A=input()
N=len(A)
for ans in range(N,2*N+1):
    now=[]
    for i in range(N):
        now.append(A[i])
    for j in range(ans-N):
        now.append(A[ans-N-j-1])
    if f(now):
        print(''.join(now))
        break