# https://yukicoder.me/problems/no/2529

MOD = 998244353

class CombinationCalculator:
    """
    modを考慮したPermutation, Combinationを計算するためのクラス
    """    
    def __init__(self, size, mod):
        self.mod = mod
        self.factorial = [0] * (size + 1)
        self.factorial[0] = 1
        for i in range(1, size + 1):
            self.factorial[i] = (i * self.factorial[i - 1]) % self.mod
        
        self.inv_factorial = [0] * (size + 1)
        self.inv_factorial[size] = pow(self.factorial[size], self.mod - 2, self.mod)

        for i in reversed(range(size)):
            self.inv_factorial[i] = ((i + 1) * self.inv_factorial[i + 1]) % self.mod

    def calc_combination(self, n, r):
        if n < 0 or n < r or r < 0:
            return 0

        if r == 0 or n == r:
            return 1
        
        ans = self.inv_factorial[n - r] * self.inv_factorial[r]
        ans %= self.mod
        ans *= self.factorial[n]
        ans %= self.mod
        return ans
    
    def calc_permutation(self, n, r):
        if n < 0 or n < r:
            return 0

        ans = self.inv_factorial[n - r]
        ans *= self.factorial[n]
        ans %= self.mod
        return ans
        

def solve(N, M):
    matrix =[[0] *3 for _ in range(3)]
    # 向き先が0
    for i in range(3):
        matrix[i][0] = 1
    # 向き先が1
    for i in range(3):
        matrix[i][1] = N - i
    # 向き先が2
    if N <= 3:
        matrix[0][2] = 0
    else:
        y = (N * (N - 3)) % MOD
        matrix[0][2] = (y * pow(2, MOD - 2, MOD)) % MOD
    
    matrix[1][2] = ((N - 3) * (N - 2)) % MOD
    matrix[1][2] *= pow(2, MOD - 2, MOD)
    matrix[1][2] %= MOD

    if N <= 3:
        matrix[2][2] = 0
    else:
        y1 = pow(N - 2, 2, MOD)
        y1 -= (N - 2)
        y1 %= MOD
        y1 *= pow(2, MOD - 2, MOD)
        y1 %= MOD
        y1 -= N - 4
        y1 %= MOD
        matrix[2][2] = y1

    dp = [0] * 3
    dp[0] = 1
    for _ in range(M):
        new_dp = [0] * 3
        for j in range(3):
            for k in range(3):
                new_dp[k] += (dp[j] * matrix[j][k]) % MOD
                new_dp[k] %= MOD
        dp = new_dp

    answer = 0
    for j in range(3):
        answer += dp[j]
        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()