Write a program which reads two integers x and y, and prints them in ascending order.
def ex(x, y):
    if x < y:
        tmp = x
        x = y
        y = tmp
    return x,y

def ex2num():
    tmp = input().split(" ")
    r1, r2 = ex(tmp[0], tmp[1])
    print (r1, r2)
    return 0

if __name__ == "__main__":
    ret = ex2num()

def ex2num():
    while (True):
        r1, r2 = input().split(" ")
        r1 = int(r1)
        r2 = int(r2)
        if (0 == r1) and (0 == r2):
            break
        if r1 < r2:
            print(r1, r2)
        else:
            print(r2, r1)

    return 0

if __name__ == "__main__":
    ret = ex2num()
