T = int(input())

P = 998244353
def calc(n,k):
    N = n
    K = k
    tmp = pow(2,N * K,P) - pow(2,(N - 1) * K,P)
    return n * tmp % P
for _ in range(T):
    n,k = map(int,input().split())
    print(calc(n,k))