mod = 998244353
TT = int(input())
assert 1 <= TT <= 10**5

Ksum = 0
for lp in range(TT):

    N,K = map(int,input().split())
    assert 0 <= N <= 10**9
    assert 1 <= K <= 200000
    Ksum += K

    ans = 0
    for i in range(1,K+1):
        ans += pow(i+1,N,mod)
        ans %= mod
    print (ans % mod)

assert Ksum <= 200000