10
-2 1
2 -2
-1 -2
0 0
2 -1
0 -2
2 2
0 2
-1 -1
1 -2
 40
-8 24
2 -1
1 -18
72 -70
5 -4
-308 436
-19 40
36 -35
-178 265
-1 2
-7 30
-1 0
3 -2
200 -285
17 -16
-35 74
0 -4
-86 106
-1 4
-7 6
0 1
-5 4
-2 3
6 -5
-4 5
181 -262
76 -118
0 0
-7 18
-58 104
-5 6
-6 12
-3 4
1 0
11 -10
-86 130
-3 6
153 -236
-183 270
-33 64
 5
0 -1
0 -2
0 -3
0 -4
0 -5
 10
0 1
-1 -1
1 1
-1 0
1 -1
-2 -1
-2 2
-2 0
0 -2
0 -1
 20
-1 18
-2 5
-5 4
2 -33
9 -18
0 0
11 -22
2 0
-1 2
-4 41
1 6
1 -2
6 -12
0 1
-3 6
3 -6
3 -8
-1 4
2 -5
1 0
 10
2 1
-1 0
-2 -1
-1 1
0 2
2 -2
0 0
-2 -2
0 -2
-2 1
 20
-3 -3
0 4
-3 1
1 1
-1 2
-4 4
3 -1
-3 0
0 2
4 0
2 3
2 4
4 -3
-4 3
-1 1
1 3
-2 4
1 -2
1 -1
3 0
 3
0 0
0 -1
0 1
 10
2 1
-1 1
0 0
-3 1
-2 -3
-1 -2
-1 -1
1 2
3 -2
0 -2
 3
3 3
1 2
1 1
 4
0 0
1 0
2 0
3 0
 9
1 1
1 0
0 1
0 0
-1 0
-1 1
-1 -1
1 -1
0 -1
 7
1 1
-1 -1
1 0
0 1
-1 0
0 -1
0 0

4
 57
 4
 5
 21
 4
 10
 1
 1
 0
 2
 8
 3

#include <iostream>
#include <algorithm>
#include <string.h>
#include <limits.h>
#include <cstdio>
#include <string>
#include <vector>
#include <cmath>
#include <map>
#define LL long long
using namespace std;
struct node
{
    int x,y;
}num[10000000];

bool cmp(node a, node b)
{
    if(a.x == b.x)  return a.y < b.y;
    return a.x < b.x;
}

int main()
{
    int i,n,j,k,m;
    scanf("%d",&n);
    for(i=0;i<n;i++)
        scanf("%d%d",&num[i].x,&num[i].y);
    k=n;
    for(i=0;i<n;i++)
        for(j=i+1;j<n;j++)
        {
            if((num[i].x + num[j].x) % 2 == 0 &&  (num[i].y + num[j].y) % 2 == 0)
            {
                num[k].x=(num[i].x + num[j].x)/2;
                num[k++].y=(num[i].y + num[j].y)/2;
            }
        }
    sort(num,num+k,cmp);
    n=k;
    j=0;
    for(i=0;i<n-1;i++)
    {
        if(num[i].x != num[i+1].x || num[i].y != num[i+1].y)
        {
            num[j].x=num[i].x;
            num[j++].y=num[i].y;
        }
    }
    num[j].x=num[n-1].x;
    num[j++].x=num[n-1].y;
    //cout<<n<<" "<<j<<endl;
    printf("%d\n",n-j);
	return 0;
}
