#5695. CSES2064 括号序列 I
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CSES2064 括号序列 I
Bracket Sequences I
Your task is to calculate the number of valid bracket sequences of length n. For example, when n=6, there are 5 sequences:
()()()
()(())
(())()
((()))
(()())
Input
The only input line has an integer n.
Output
Print the number of sequences modulo 10^9+7.
Constraints
Example
Input
6
Output
5