# https://yukicoder.me/problems/no/3464

MOD= 998244353

def solve(N, M):
    base = pow(2, N, MOD)
    base -= 1
    base %= MOD
    base = pow(base, M, MOD)

    poly = pow(2, M, MOD)
    poly -= 1
    poly %= MOD
    poly =pow(poly, N, MOD)

    p = pow(2, N * M, MOD)

    answer = (base + poly) % MOD
    answer -= p
    answer %= MOD

    return answer



def main():
    T = int(input())
    answers = []
    for _ in range(T):
        N, M = map(int, input().split())
        ans = solve(N, M)
        answers.append(ans)

    for ans in answers:
        print(ans)







if __name__ == "__main__":
    main()