while True:
    t = int(input())
    if t >=1 and t<=100000:
        break

for i in range(t):
    while True:
        x = int (input())
        y = int (input())
        if (x>=1 and  x<=1000000000):
            if (y>=1 and  y<=1000000000):
                break

    if y >= x:
        print (y)
        continue
    else:
        for k in range (x, 9999):
            if k % y == 0:
                print (k)
                break