mod=998244353

M=(10**5)*3+1 
fac=[1]*M
ninv=[1]*M
finv=[1]*M
for i in range(2,M):
  fac[i]=fac[i-1]*i%mod
  ninv[i]=(-(mod//i)*ninv[mod%i])%mod
  finv[i]=finv[i-1]*ninv[i]%mod

def binom(n,k):
  if n<0 or k<0:
    return 0
  if k>n:
    return 0
  return (fac[n]*finv[k]%mod)*finv[n-k]%mod

from sys import stdin
input=lambda :stdin.readline()[:-1]

def solve():
  n,m=map(int,input().split())
  ans=0
  for i in range(m):
    ans+=binom(n-1,i)
    ans%=mod
  ans*=pow(2,n)-1
  print(ans%mod)



for _ in range(int(input())):
  solve()