import sys

# sys.setrecursionlimit(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 = 18446744073709551615
# inf = 4294967295
# md = 10**9+7
md = 998244353

n = 4001
# n = 20
dp = [[0]*n for _ in range(n)]

for i in range(n): dp[i][0] = 1
for i in range(n): dp[0][i] = 1

for i in range(1,n):
    for j in range(1,n):
        if i == j == 0: continue
        if i and j: dp[i][j] += dp[i-1][j-1]*2%md
        if i: dp[i][j] += dp[i-1][j]
        if j: dp[i][j] += dp[i][j-1]
        dp[i][j] %= md

for i in range(n-1):
    for j in range(n-1):
        dp[i+1][j+1] += dp[i][j]
        dp[i+1][j+1] %= md
# p2D(dp)

for _ in range(II()):
    x, y = LI()
    print(dp[x][y])