import sys input = sys.stdin.readline from collections import * xy = [(-10**9, -10**9)] add_y = 1 while True: x, y = xy[-1][0]+1, xy[-1][1]+add_y if y>10**9: break xy.append((x, y)) add_y += 1 print(len(xy)) sys.stdout.flush() for x, y in xy: print(x, y) sys.stdout.flush()