The Last Non-zero Digit
By Shahriar Manzoor 
Bangladesh
By Shahriar Manzoor Bangladesh
In this problem it will be given to you two decimal integer numbers N, M. You will have to find the last non-zero digit of the NPM. This means no of permutations of N things taking M at a time.
The input file contains several lines of input. Each line of the input file contains two integers N (0 ≤ N ≤ 20000000), M (0 ≤ N). Input is terminated by end-of-file.
For each line of the input file you should output a single digit, which is the last non-zero digit of NPM. For example, if NPM is 720 then the last non-zero digit is 2. So in this case your output should be 2.
| Sample Input | Sample Output |
|
10 10 |
8 |