h,w = map(int,input().split())
li = []
for i in range(h):
    ls = list(map(int,input().split()))
    li += ls
li = sorted(li)
for i in range(h):
    le = ""
    for j in range(w):
        le += str(" ") + str(li[i*w+j])
    print(le[:0])