Catalan Number Computation

The Catalan numbers form a sequence of natural numbers that appear in various counting problems, often involving recursively defined structures. The n-th Catalan number is defined by the recurrence relation:

\(C_0 = 1\) and for \(n \ge 1\), \(C_n = \sum_{i=0}^{n-1} C_i \cdot C_{n-i-1}\).

Given an integer \(n\), your task is to compute the n-th Catalan number.

inputFormat

The input consists of a single integer \(n\) (0 \(\leq\) n \(\leq\) 20) provided on a single line from standard input.

outputFormat

Output the n-th Catalan number as an integer to standard output.

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