import sys

# sys.setrecursionlimit(1000005)
# sys.set_int_max_str_digits(200005)
int1 = lambda x: int(x)-1
pDB = lambda *x: print(*x, end="\n", file=sys.stderr)
p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr)
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()

# dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
# inf = -1-(-1 << 31)
inf = -1-(-1 << 63)
# md = 10**9+7
md = 998244353

def dot(aa, bb):
    h = len(aa)
    w = len(bb[0])
    res = [[0]*w for _ in range(h)]
    for j, col in enumerate(zip(*bb)):
        for i in range(h):
            v = 0
            # for a, b in zip(row, col): v += a*b
            # res[i][j] = v
            for a, b in zip(aa[i], col): v += a*b%md
            res[i][j] = v%md
    return res

def matpow(mat, e):
    n = len(mat)
    res = [[1 if i == j else 0 for j in range(n)] for i in range(n)]
    while e:
        if e & 1: res = dot(res, mat)
        mat = dot(mat, mat)
        e >>= 1
    return res

def solve():
    w, h = LI()
    if w == 2:
        mat = [[1, 2, 0],
               [1, 1, 0],
               [0, 0, 0]]
    else:
        c = w*(w-1)//2-w
        mat = [[1, w, c],
               [1, w-1, c-w+3],
               [1, w-2, c-2*(w-3)+1]]
    mat = matpow(mat, h)
    print(sum(mat[0])%md)

for _ in range(II()): solve()