# Enter your code here. Read input from STDIN. Print output to STDOUT
import math
def c():
	[a, b] = raw_input().split()
	a = int(a)
	b = int(b)
	c = a - b +1
	d = c - b
	if d > 0:
		e = math.factorial(c) / (math.factorial(b) * math.factorial(d))
	else:
		e = 0

	return e

n = int(raw_input())
r =[]
for i in range(n):
	r.append(c())

for i in r:
	print i