import sys

sys.set_int_max_str_digits(10**6 + 5)

t = int(input())
for i in range(t):
    n1, m1 = input().split()
    n, m = map(int, [n1, m1])
    if n < m:
        print(m)
        continue
    a1 = (n // m + 1) * m
    a1 = str(a1)
    n += 1
    n1 = str(n)
    if m1 in n1:
        print(n1)
        continue

    lm = len(m1)
    n21 = n1[: -2 * lm + 1]
    n2 = n1[-2 * lm + 1 :]
    a2 = "9" * len(n2)
    lst = n2[-lm:]
    # print(n2)
    for i in range(0, len(n2) - lm + 1):
        ok = 1
        for j in range(0, len(n2) - i - lm):
            if n2[i + j] != m1[j]:
                ok = 0
                break
        j = len(n2) - i - lm
        # print(f"{j, ok}")
        if ok == 0:
            continue

        a3 = m1[-i - 1 :] + "0" * (len(n2) - lm - i)
        if a3 > n2:
            a2 = min(a2, a3)
        # print(f"{m1 = },{a3 = }")
        # a3 = n2[:i] + m1 + "0" * (len(n2) - lm - i)
        # if a3 >= n2:
        #     a2 = min(a2, a3)

    a2 = n2[:-lm] + a2
    # print(a2)
    if len(a1) < len(a2):
        print(a1)
    elif len(a2) < len(a1):
        print(a2)
    else:
        print(min(a1, a2))

"""
6
7 3
12 3
9 10
249 51
1369 37
2 1

1
100000000001244 453

1
249 51

"""