"""

"""

import sys
from sys import stdin
import math

def Monotone_Chain(vlis):

    def upstate(a,b,c):
        B = (b[0]-a[0],b[1]-a[1])
        C = (c[0]-a[0],c[1]-a[1])
        return B[1] * C[0] < C[1] * B[0]

    def downstate(a,b,c):
        B = (b[0]-a[0],b[1]-a[1])
        C = (c[0]-a[0],c[1]-a[1])
        return B[1] * C[0] > C[1] * B[0]

    N = len(vlis)
    vc = [vlis[i] for i in range(N)]

    if N >= 3:
        
        vc.sort()

        uv = []

        for v in vc:
            uv.append(v)
            while len(uv) >= 3 and upstate(uv[-3],uv[-2],uv[-1]):
                del uv[-2]

        dv = []
        for v in vc:
            dv.append(v)
            while len(dv) >= 3 and downstate(dv[-3],dv[-2],dv[-1]):
                del dv[-2]


        #print (uv,dv)
        tmp = dv[1:-1]
        tmp.reverse()
        uv += tmp

        return uv

    else:
        return vc

N = 10**6

lis = []

D = 10**9

for i in range(N):

    r = (i * 2*math.pi) / N
    lis.append(( int(D * math.cos(r)) , int(D * math.sin(r))  ))


ans = Monotone_Chain(lis)
ans.reverse()

print (len(ans))
for tup in ans:
    print (tup[0],tup[1])