s = gets.to_i
@memo = Hash.new(0)

def func(n,i)
    return i if @memo[n] == 2
    if i == 0
        @memo[n]=1
        return func(n,i+1) 
    end

    if n.even?
        n = n/2
    elsif n.odd?
        n = (3*n)+1
    end
    return func(n,i+1) if @memo[n] += 1
    return @memo[n] = func(n,i+1)
end

puts func(s,0)