while True: try: a, b = map(int, input().split()) num = list(map(int, input().split())) count = 0 while len(num): print(num.pop(0), end = ' ') count += 1 if count == b: print() count = 0 except: break
while True: try: a, b = map(int, input().split()) num = list(map(int, input().split())) count = 0 while len(num): print(num.pop(0), end = ' ') count += 1 if count == b: print() count = 0 except: break