The Last Non-zero Digit

Time Limit
1s
Memory Limit
65536KB
Judge Program
Standard
Ratio(Solve/Submit)
100.00%(1/1)
Description:

In this problem you will be given two decimal integer number 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.

Input:

The input contains several lines of input. Each line of the input file contains two integers N (0 <= N<= 20000000), M (0 <= M <= N).

Output:

For each line of the input 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:
10 10
10 5
25 6
Sample Output:
8
4
2
Submit