import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################

mod = 998244353
nn = 10**6
fact = [1] * nn
for i in range(nn - 1):
    fact[i + 1] = fact[i] * (i + 1) % mod
invfact = [1] * nn
invfact[nn - 1] = pow(fact[nn - 1], mod - 2, mod)
for i in range(nn - 1)[::-1]:
    invfact[i] = invfact[i + 1] * (i + 1) % mod
 
def binom(x, y):
    if x < 0 or y < 0 or x - y < 0:
        return 0
    return fact[x] * invfact[y] % mod * invfact[x - y] % mod

que = []
t = ni()
B = 500
ans = [None] * t
for _ in range(t):
    n,m = na()
    que.append((n//B, m, n, _))

que = sorted(que)

sm, sn = 1, 1
sum = 1
z = pow(2, mod-2, mod)
for q in que:
    _, m, n, i = q
    #print(sum)
    if sm < m:
        for x in range(sm, m):
            sum += binom(sn-1, x)
            sum %= mod
    else:
        for x in range(sm, m, -1):
            sum -= binom(sn-1, x-1)
            sum %= mod
    if sn < n:
        for x in range(sn, n):
            sum = (sum * 2 - binom(x-1, m-1))%mod
    else:
        for x in range(sn, n, -1):
            sum = (sum + binom(x-2, m-1))*z %mod
    sum %= mod
    ans[i] = sum * (pow(2, n, mod)-1)%mod
    sn, sm  = n, m
print(*ans, sep = "\n")