Even Digit Product

Given a non-negative integer \(N\), compute the product of all the even digits in \(N\). If \(N\) does not contain any even digits, the product is defined to be \(1\).

Note that \(0\) is considered an even digit. Multiplying by \(0\) will yield an overall product of \(0\). For example, if \(N = 4821\), the even digits are \(4\), \(8\), and \(2\), and the product is \(4 \times 8 \times 2 = 64\).

inputFormat

The input consists of a single line containing a non-negative integer \(N\) represented in decimal form. There are no extra spaces or delimiters.

outputFormat

Output a single integer: the product of all even digits in \(N\). If there are no even digits, output \(1\).

4821

64