翻译11

https://acs.jxnu.edu.cn/problem/HDU1041
Computer Transformation
描述：
A sequence consisting of one digit, the number 1 is initially written into a computer. At each successive time step, the computer simultaneously tranforms each digit 0 into the sequence 1 0 and each digit 1 into the sequence 0 1. So, after the first time step, the sequence 0 1 is obtained; after the second, the sequence 1 0 0 1, after the third, the sequence 0 1 1 0 1 0 0 1 and so on.
How many pairs of consequitive zeroes will appear in the sequence after n steps?
输入：
Every input line contains one natural number n (0 < n ≤1000).
输出：
For each input n print the number of consecutive zeroes pairs that will appear in the sequence after n steps.

翻译
电脑转换
描述：
由一个数字1组成的序列，最初被写入计算机。在每个连续的时间步长中，计算机同时将数字0转换成序列10和将数字1转换成序列01。所有，第一次时间步后，获得序列01；第二次后，序列1001，第三次后，序列01101001，以此类推。
n步后序列中会出现几对连续的0？
输入：
每个输入行包含一个自然数n(0 < n ≤1000)。
输出：
对于每个输入n，输出n步后关于序列中连续出现的0对的数量。