//#include <tourist>
#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
typedef long long ll;
typedef long double ld;
typedef unsigned int uint;
typedef unsigned long long ull;

typedef pair<ll, ll> p;
const int INF = 1e9;
const double eps = 1e-7;
const ll LINF = ll(1e18);
const int MOD = 1000000007;
const int dx[4] = {0, 1, 0, -1}, dy[4] = {-1, 0, 1, 0};
const int Dx[8] = {0, 1, 1, 1, 0, -1, -1, -1}, Dy[8] = {-1, -1, 0, 1, 1, 1, 0, -1};
const long double pi = 4 * atan(1);
#define yes cout << "Yes" << endl
#define YES cout << "YES" << endl
#define no cout << "No" << endl
#define NO cout << "NO" << endl
#define rep(i, n) for (int i = 0; i < n; i++)
#define ALL(v) v.begin(), v.end()
#define debug(v)          \
    cout << #v << ":";    \
    for (auto x : v)      \
    {                     \
        cout << x << ' '; \
    }                     \
    cout << endl;
template <class T>
bool chmax(T &a, const T &b)
{
    if (a < b)
    {
        a = b;
        return 1;
    }
    return 0;
}
template <class T>
bool chmin(T &a, const T &b)
{
    if (b < a)
    {
        a = b;
        return 1;
    }
    return 0;
}
template <typename T>
istream &operator>>(istream &is, vector<T> &v)
{
    for (T &x : v)
        is >> x;
    return is;
}
//cout<<fixed<<setprecision(15);有効数字15桁
//-std=c++14
//g++ yarudake.cpp -std=c++17 -I .
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }

ostream &operator<<(ostream &dest, __int128_t value)
{
    ostream::sentry s(dest);
    if (s)
    {
        __uint128_t tmp = value < 0 ? -value : value;
        char buffer[128];
        char *d = std::end(buffer);
        do
        {
            --d;
            *d = "0123456789"[tmp % 10];
            tmp /= 10;
        } while (tmp != 0);
        if (value < 0)
        {
            --d;
            *d = '-';
        }
        int len = end(buffer) - d;
        if (dest.rdbuf()->sputn(d, len) != len)
        {
            dest.setstate(ios_base::badbit);
        }
    }
    return dest;
}

__int128 parse(string &s)
{
    __int128 ret = 0;
    for (int i = 0; i < s.length(); i++)
        if ('0' <= s[i] && s[i] <= '9')
            ret = 10 * ret + s[i] - '0';
    return ret;
}
int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    __int128 n,m;
    ll temp;
    cin>>temp;
    n=temp;
    __int128 ans =1;
    n-=1;
    rep(i,11){
        ans*=n;
        n--;
    }
    rep(i,11){
        ans/=i+1;
    }
    cout<<ans<<"\n";
}

#include <iostream>
#include <string>
#include <cmath>
#define rep(i, n) for(int i=0;i<n;i++)
using namespace std;

int main(){
    int n, sum=0;
    cin >> n;
    double x[n], y[n];
    double a;
    rep(i, n){
        cin >> x[i] >> y[i];
    }

    rep(i, n){
        rep(j, i){
            a = (y[j]-y[i])/(x[j]-x[i]);
            if(a >= -1 && 1 >= a){
                sum++;
            }
        }
    }

    cout << sum << endl;
    return 0;
}