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.sort()
for i in range(H):
    for j in range(W):
        A[i][j] = B[i*W+j]
    print(*A[i])