def factorial(n):
    if n == 0:
        fact = 1
    while n :
        fact = fact * n
        n = n - 1
    return fact

count = int(raw_input())
while count:
    n = int(raw_input())
    m = int(raw_input())
    fact = factorial(n)/factorial(n-m)
    print (fact)
    count = count-1