The Last Non-zero Digit
Time Limit: 1000MS
Memory Limit: 65536K
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.
The input contains several lines of input. Each line of the input file contains two integers N (0 <= N<= 20000000), M (0 <= M <= N).
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.