def f5(n):
    i = n
    while i > 0:
        j = i
        while j > 0:
            print(i, j)
            j = j - 1
        i = i // 2

def f6(n):
    i = n
    while i > 0:
        j = i
        while j > 0:
            print(i, j)
            j = j // 2
        i = i - 1