H,W = map(int,input().split())

l = []
for _ in range(H):
    tmp = list(map(int,input().split()))
    for t in tmp:
        l.append(t)
l.sort()
ans = []
for i in range(H*W):
    ans.append(l[i])
    if i > 0 and (i+1)%W == 0:
        print(*ans)
        ans = []