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

for i in range(h):
    for j in range(w):
        b.append(a[i][j])

b_so = sorted(b)

for x in range(w, h * w + w, w):
    print(*b_so[x - w:x])