def Main():
    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):
            print(b[w*i+j],end=" ")
        print()


Main()