3406 -- Last digit

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Last digit

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 3318		Accepted: 1013

Description

Determine the last nonzero digit in value of expression

$C_n^m=\frac{n!}{m!(n-m)!}$ .

Input

The input contains a single line with n and m separated by one or several spaces; n, m are natural numbers from 1 to 1000000, n ≥ m.

Output

The output contains a single line with the last nonzero digit.

Sample Input

4 2

Sample Output

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