You are going to hold a competition of one-to-one game called AtCoder Janken. _(Janken is the Japanese name for Rock-paper-scissors.)_ N players will participate in this competition, and they are given distinct integers from 1 through N. The arena has M playing fields for two players. You need to assign each playing field two distinct integers between 1 and N (inclusive). You cannot assign the same integer to multiple playing fields. The competition consists of N rounds, each of which proceeds as follows:    * For each player, if there is a playing field that is assigned the player's integer, the player goes to that field and fight the other player who comes there.   * Then, each player adds 1 to its integer. If it becomes N+1, change it to 1.  You want to ensure that no player fights the same opponent more than once during the N rounds. Print an assignment of integers to the playing fields satisfying this condition. It can be proved that such an assignment always exists under the constraints given.
N, M = map(int, input().split())
for i in range(M):
    print(1 + i, N - i)
N, M = map(int, input().split())
if N % 2 == 0:
    num = 0
    mid = N // 2
    for i in range(M):
        print(mid - i, mid + 1 + i)
        num += 1
        if num == M:
            break
        print(1 + i, N - 1 - i)
        num += 1
        if num == M:
            break
else:
    mid = (N + 1) // 2
    for i in range(M):
        print(mid - i, mid + 1 + i)