from heapq import *
from itertools import *
from functools import *
from collections import *
import sys,math
input = sys.stdin.readline

mod = 998244353
def answer():
    
    N,K = map(int,input().split())
    
    print(N*(pow(2,N*K,mod) - pow(2,(N-1)*K,mod))%mod)

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