问题2610--Ignatius and the Princess III

2610: Ignatius and the Princess III

[命题人 : ]
时间限制 : 1.000 sec  内存限制 : 64 MB

题目描述

"Well, it seems the first problem is too easy. I will let you know how foolish you are later." feng5166 says. "The second problem is, given an positive integer N, we define an equation like this: N=a[1]+a[2]+a[3]+...+a[m]; a[i]>0,1<=m<=N; My question is how many different equations you can find for a given N. For example, assume N is 4, we can find: 4 = 4; 4 = 3 + 1; 4 = 2 + 2; 4 = 2 + 1 + 1; 4 = 1 + 1 + 1 + 1; so the result is 5 when N is 4. Note that "4 = 3 + 1" and "4 = 1 + 3" is the same in this problem. Now, you do it!"

输入

The input contains several test cases. Each test case contains a positive integer N(1<=N<=120) which is mentioned above. The input is terminated by the end of file.

输出

For each test case, you have to output a line contains an integer P which indicate the different equations you have found.

样例输入 Copy

4
10
20

样例输出 Copy

5
42
627

来源/分类

hdu