A = input()
N = len(A)
mid_start = N//2
ans1 = 'X'*300
ans2 = 'X'*300

# 中心が1文字の場合と2文字の場合がある
for mid in range(mid_start, N):
    post_mid = A[mid:]
    pre_mid = A[mid+1-(N-mid):mid+1][::-1]
    #print('mid', mid, post_mid, pre_mid)
    if post_mid == pre_mid:
        ans1 = A + A[:mid+1-(N-mid)][::-1]
        print(ans1)
        break
    
for mid in range(mid_start, N):
    post_mid = A[mid:]
    pre_mid = A[mid-(N-mid):mid][::-1]
    #print('mid', mid, post_mid, pre_mid)
    if post_mid == pre_mid:
        ans2 = A + A[:mid-(N-mid)][::-1]
        print(ans2)
        break
        
if len(ans1) <= len(ans2):
    print(ans1)
else:
    print(ans2)