import sys
from collections import deque, Counter
input = lambda: sys.stdin.readline().rstrip()
ii = lambda: int(input())
mi = lambda: map(int, input().split())
li = lambda: list(mi())
inf = 2 ** 63 - 1
mod = 998244353

class Combinatorics():
    def __init__(self, mod, maxi):
        self.mod = mod
        self.maxi = maxi
        self.facs = [1] * (maxi + 1)
        self.factinvs = [1] * (maxi + 1)
        self.invs = [1] * (maxi + 1)
        for i in range(2, self.maxi + 1):
            self.facs[i] = ((self.facs[i-1] * i) % self.mod)
            self.invs[i] = (-self.invs[self.mod % i] * (self.mod // i)) % self.mod
            self.factinvs[i] = (self.factinvs[i-1] * self.invs[i]) % self.mod
            
    def choose(self, n, k) -> int:
        if k < 0 or k > n: return 0
        if k == 0 or k == n: return 1
        k = min(k, n - k)
        return (((self.facs[n] * self.factinvs[k]) % self.mod) * self.factinvs[n-k]) % self.mod
    
    def perm(self, n, k) -> int:
        return (self.choose(n, k) * self.facs[k]) % self.mod

    def homop(self, n, k) -> int:
        if n == k == 0:
            return 1
        return self.choose(n + k - 1, k)

t = 500
maxi = 2 * 10 ** 5
C = Combinatorics(mod, maxi)
pre = [[0] * (maxi // t + 1) for _ in range(maxi // t + 1)]
for i in range(0, maxi + 1, t):
    for j in range(0, maxi + 1, t):
        if j // t > 0:
            pre[i // t][j // t] += pre[i // t][j // t - 1]
            for k in range(j - t + 1, j + 1):
                pre[i // t][j // t] += C.choose(i, k)
        else:
            pre[i//t][j//t] = 1

def Csum(n, k):
    nnow = (n // t) * t
    know = (k // t) * t
    now = pre[n // t][k // t]
    for i in range(n - nnow):
        now = 2 * now - C.choose(nnow + i, know)
        now %= mod

    for i in range(k - know):
        now = now + C.choose(n, know + i + 1)
        now %= mod
    return now
def solve():
    n, m = mi()
    ans = Csum(n - 1, m - 1) * (pow(2, n, mod) - 1)
    ans %= mod
    print(ans)
for _ in range(ii()):
    solve()