h,w = map(int,input().split())
A = [list(map(int,input().split())) for _ in range(h)]
A = sum(A,[])
A.sort()
for i in range(h*w):
    if (i+1) % w == 0:
        print(A[i],end="\n")
    else:
        print(A[i],end=" ")