import sys
input = sys.stdin.readline
from collections import *

xy = [(0, -10**9)]
add_y = 0

while True:
    x, y = xy[-1][0]+1, xy[-1][1]+add_y
    
    if y>0:
        break
    
    xy.append((x, y))
    add_y += 1

while True:
    x, y = xy[-1][0]-1, xy[-1][1]+add_y
    
    if add_y==0:
        break
    
    xy.append((x, y))
    add_y -= 1

add_y -= 1

while True:
    x, y = xy[-1][0]-1, xy[-1][1]+add_y
    
    if y<0:
        break
    
    xy.append((x, y))
    add_y -= 1

while True:
    x, y = xy[-1][0]+1, xy[-1][1]+add_y
    
    if add_y==-1:
        break
    
    xy.append((x, y))
    add_y += 1

print(len(xy))
sys.stdout.flush()

for x, y in xy:
    assert(-10**9<=x<=10**9 and -10**9<=y<=10**9)
    print(x, y)
    sys.stdout.flush()