MOD = 998244353
def solve(n,k):
    ans = pow(pow(2,n,MOD),k,MOD)-pow(pow(2,n-1,MOD),k,MOD)
    ans *= n
    ans %= MOD
    print(ans)

for _ in range(int(input())):
    N,K = map(int,input().split())
    solve(N,K)