def convert_1d_to_2d(s, c):
    return [s[i:i + c] for i in range(0, len(s), c)]

h, w = map(int, input().split())

s = [list(map(int, input().split())) for _ in range(h)]

t = []
for i in range(h):
    for j in range(w):
        t.append(s[i][j])

t.sort()

li = convert_1d_to_2d(t, w)

for i in range(h):
    print(*li[i])