Write a program to calculate nPr. nPr represents n permutation r and value of nPr is (n!) / (n-r)!.
Input: The first line of the input contains T denoting the number of testcases. First line of the test case will be the value of n and r respectively.
Output: For each test case output will be the value of nPr.
1 <=n,r<= 20