import sys
input=lambda: sys.stdin.readline().rstrip()
h,w=map(int,input().split())
T=[]
for _ in range(h):
	T+=[int(i) for i in input().split()]
T.sort()
Ans=[[0]*w for _ in range(h)]
for i in range(h*w):
	ih,iw=i//w,i%w
	Ans[ih][iw]=T[i]
for i in range(h):
	print(*Ans[i])