S=raw_input()
ans=0
for i in range(len(S)):
    for j in range(i,len(S)):
        if i==0 and j==len(S)-1:
            continue
        I,J=i,j
        ok=True
        while I<J:
            if S[I]!=S[J]:
                ok=False
                break
            I+=1
            J-=1
        if ok:
            ans=max(ans,j-i+1)
print ans