题目描述
Labor day is coming.Since the holiday is long,Many students are planning to have a tour. The Taishan Mountain is very beautiful, so WangPeng and his classmates want to climb the Taishan Mountain. Mountaineering sports is WangPeng's avocation, so he is very excited. Suddenly, a very amusing idea comes to him. The Taishan Mountain has many stairs, and he can climb the mountain one step by 2 stairs or by 1 stairs. How many ways does he have to climb the mountain? For example, the stairs is 2, he has 2 ways.The first one is the first step by 1 stair, and the next step by 1 stair.And the second way is only one step by 2 stairs.
输入
The input is including many test cases. Every line is one test case with a integer number N(N<=20). N is the stairs of the Taishan Mountain.
输出
You should output how many ways WangPeng can climb the mountain, each case output a line.