#include <bits/stdc++.h>
using namespace std;
#ifdef __local_leywar
#include <debug/debugger.h>
#endif
#define int long long
#define endl '\n'
const int INF = 2e9,
MOD = 1e9+7,
INFLL = 1e18;
using pii = pair<int, int>;
mt19937_64 rng(time(0));
pii operator - (pii a, pii b)
{
return (pii){a.first - b.first, a.second - b.second};
}
int32_t main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int n;
cin >> n;
vector<pii> ar(n);
for(auto &i: ar)
cin >> i.first >> i.second ;
for(int i = n - 1 ; i >= 0 ; i--)
{
ar[i] = ar[i] - ar[0];
}
int ans = 0;
vector<int> dp(n, INFLL);
vector<bool> flag(n);
dp[0] = 0;
while(true)
{
int dist = INFLL, nod = -1;
//db(dp);
for(int i = 0 ; i < n ; i++)
if(!flag[i] and dp[i] < dist)
dist = dp[i], nod = i;
//db(dist, nod);
if(nod == -1)
break;
ans++;
flag[nod] = true;
for(int i = 0 ; i < n ; i++)
{
pii temp = ar[nod] - ar[i];
//db(ar[nod], ar[i], temp);
//dbl(!flag[i], abs(temp.first) == abs(temp.second), dist <= abs(temp.first), dp[nod] > abs(temp.first));
if(!flag[i] and abs(temp.first) == abs(temp.second) and dist <= abs(temp.first) and dp[i] > abs(temp.first))
dp[i] = abs(temp.first);
}
}
cout << ans ;
return 0;
}
