# 1010 다리 놓기

t = int(input())

n = [0]*t
m = [0]*t 
for i in range(t):
  n[i],m[i] =  map(int,input().split())

for i in range(t):
  dp = [0]* n[i]
  dp[0] = m[i]

  for j in range(1,n[i]): 
    dp[j] = dp[j-1]*(m[i]-j)//(j+1)

  print(dp[n[i]-1])