CSES - Two Sets II
- Time limit: 1.00 s
- Memory limit: 512 MB
Your task is to count the number of ways numbers 1,2,…,n can be divided into two sets of equal sum.
For example, if n=7, there are four solutions:
- {1,3,4,6} and {2,5,7}
- {1,2,5,6} and {3,4,7}
- {1,2,4,7} and {3,5,6}
- {1,6,7} and {2,3,4,5}
The only input line contains an integer n.
Output
Print the answer modulo 109+7.
Constraints
- 1≤n≤500
Example
Input:
7
Output:
4