Computing the exact number of ways that N things can be taken M at a time can be a great challenge when N and/or M become very large. Challenges are the stuff of contests. Therefore, you are to make just such a computation given the following: and M ≤N For the record, the exact value of 100! is: 93,326,215,443,944,152,681,699,238,856,266,700,490,715,968,264,381,621, 468,592,963,895,217,599,993,229,915,608,941,463,976,156,518,286,253, 697,920,827,223,758,251,185,210,916,864,000,000,000,000,000,000,000,000 Input The input to this program will be one or more lines each containing zero or more leading spaces, a value for N, one or more spaces, and a value for M. The last line of the input file will contain a dummy N, M pair with both values equal to zero. Your program should terminate when this line is read. Output The output from this program should be in the form: N things taken M at a time is C exactly. Sample Input 100 6 20 5 18 6 00 Sample Output 100 things taken 6 at a time is 1192052400 exactly. 20 things taken 5 at a time is 15504 exactly. 18 things taken 6 at a time is 18564 exactly. GIVEN: Compute the EXACT value of: 5≤N ≤100, and 5≤M ≤100, C= N! (N − M)! × M! You may assume that the final value of C will fit in a 32-bit Pascal LongInt or a C long.