MOD = 998244353

N = 4000
A = [[0] * N for _ in range(N)]
for i in range(N):
    A[0][i] = 5 + 3 * i
    A[i][0] = 5 + 3 * i

for i in range(1, N):
    for j in range(1, N):
        A[i][j] = A[i - 1][j] + A[i][j - 1] + 2 * A[i - 1][j - 1]
        if i == j:
            A[i][j] += 1
        A[i][j] %= MOD

Q = int(input())
for _ in range(Q):
    x, y = map(int, input().split())
    print(A[x - 1][y - 1])