h, w = map(int, input().split())
g = []
for _ in range(h):
    g.append(list(map(int, input().split())))
d = []
for i in range(h):
    for j in range(w):
        d.append(g[i][j])
d.sort()
p = []
for i, v in enumerate(d):
    p.append(v)
    if (i+1) % w == 0:
        print(*p)
        p = []