class mod_int: #素数を法とした自然数, または有理数を扱うことのできるクラス
	def __init__(self, value, mod):
		self.value = value % mod
		self.mod = mod
	def __neg__(self):
		return mod_int(-self.value, self.mod)
	def __add__(self, other):
		if type(other) == mod_int:
			return mod_int(self.value + other.value, self.mod)
		elif type(other) == int:
			return mod_int(self.value + other, self.mod)
		raise TypeError()
	def __sub__(self, other):
		return self + (-other)
	def __mul__(self, other):
		if type(other) == mod_int:
			return mod_int(self.value * other.value, self.mod)
		elif type(other) == int:
			return mod_int(self.value * other, self.mod)
		raise TypeError()
	def __truediv__(self, other):
		if type(other) in [mod_int, int]:
			return self * other ** (self.mod - 2)
		raise TypeError()
	def __pow__(self, other):
		if type(other) != int:
			raise TypeError()
		cur, ret = self.value, 1
		while other > 0:
			if other % 2:
				ret = (ret * cur) % self.mod
			other //= 2
			cur = (cur ** 2) % self.mod
		return mod_int(ret, self.mod)
	def __repr__(self):
		return str(self.value)
T = int(input())
mod = 998244353
for i in range(T):
	N, K = map(int, input().split())
	temp = mod_int(1, mod)
	one = mod_int(1, mod)
	ans = mod_int(0, mod)
	for i in range(K):
		temp += one
		ans += temp ** N
	print(ans)