Points:
1600 (p)
Time limit:
1.0s
Memory limit:
512M
Input:
stdin
Output:
stdout
Your task is to count the number of ways numbers \(1,2,\ldots, n\) 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 \(\{2,3,4,5\}\)
Input
- The only input line contains an integer \(n\).
Output
- Print the answer modulo \(10^9+7\).
Constraints
- \(1 \leq n \leq 500\)
Example
Sample input
7
Sample output
4
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