[/code]n=int(raw_input())
i=0
for i in range(0,n):
a,b=([long(x) for x in raw_input().split()])
w,q,e,j=1,1,1,1
if(a==0 and b==0):
print 0
continue;
s=a-b
r=s+b-1
t=b-1
for j in range(1,t+1):
q*=j
j=j+1
for j in range(1,r+1):
w*=j
j=j+1
for j in range(1,s+1):
e*=j
j=j+1
print w/(e*q)
i=i+1
i am getting WA.can anyone help me out .