mapping = Struct.new(:rmin, :rmax)
str = gets.strip
n = str.length
(n - 2).downto(0) do |i|
    0.upto(n - i - 1) do |j|
        nstr = str[j, i + 1]
        find = false
        ((i + 1) / 2).times do |k|
            if nstr[k] != nstr[i - k]
                find = true
                break
            end
        end
        if !find
            puts nstr.length
            exit
        end
    end
end