import sys; input = sys.stdin.buffer.readline
sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	H, W = getlist()
	L = []
	for i in range(H):
		a = getlist()
		L += a

	L.sort()
	ans = [[0] * W for i in range(H)]
	for i in range(H):
		for j in range(W):
			ans[i][j] = L[i * W + j]

	for i in range(H):
		print(*ans[i])



if __name__ == '__main__':
	main()