#include<bits/stdc++.h>
using namespace std;

//#pragma GCC optimize("Ofast,unroll-loops,no-stack-protector")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")


#define pb push_back
#define fi first
#define se second
#define ll long long
#define tp top()
#define fr front()
#define vi vector<int>
#define sz size()
#define rep(i,a,b) for(int i = a; i < b; ++i)
#define mem(a,  b) memset(a,  (b),  sizeof(a))
#define clr(a) memset(a,  0,  sizeof(a))
#define sqr(x) ( (x) * (x) )
#define all(v) v.begin(),  v.end()

typedef pair<int, int> pii;
typedef pair<int,pii> pip;
typedef pair<pii,int> ppi;
typedef pair<pii,pii> ppp;



void base(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
}

//double dist(double x1, double y1, double x2, double y2){
//	return hypot(x1-x2,y1-y2);
//}

struct point {
    double x,y;
    point() {
        x=y=0.0;
    }
};

bool collinear(point P, point L, point R) { //newly added(luis), cek 3 poin segaris
    return P.x*(L.y-R.y)+L.x*(R.y-P.y)+R.x*(P.y-L.y)==0; // bole gnti “dabs(x)<EPS”
}


point ps[120];
//double x[120], y[120];
void solve(){
	int n; cin>>n;
	rep(i,0,n) cin>>ps[i].x>>ps[i].y;
	bool v=0;
	rep(i,0,n) rep(j,i+1,n) rep(k,0,n){
		if (k==i || k==j)  continue;
		if (collinear(ps[i],ps[j],ps[k])) {
			v = 1;
		}
	}
	if (v) cout<<"Yes\n";
	else cout<<"No\n";
}

int main()
{
	base();
//  freopen("input.txt", "r", stdin);
//  freopen("output.txt", "w", stdout);
	int t=1;
//	cin>>t;
	while(t--){
		solve();
	}
	return 0;
}





//Keep calm and carry on..

/*  Problem :
    URL :
*/

#include<bits/stdc++.h>

using namespace std;
typedef long long int ll;
typedef unsigned long long int ull;
typedef long double ld;


# define fast           ios_base::sync_with_stdio(false),cin.tie(NULL),cout.tie(NULL);
# define pb             push_back
# define pi             3.1415926535897932384626
# define mod            1000000007
# define endl          '\n'
# define DEBUG          false
# define F              first
# define S              second
# define loop1(i,a,b)   for(ll i = a; i<b; i++)
# define loop2(i,a,b)   for(ll i = b-1; i>=a; i--)
# pragma GCC optimize "trapv"

void just_solved_it() {

	ld sx, sy, gx, gy;
	cin >> sx >> sy >> gx >> gy;
	ld ans = (gy*sx + sy*gx)/ (sy + gy);
    cout << fixed << setprecision(12) << ans ;
}

int main() {

#ifndef ONLINE_JUDGE
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
#endif

	fast;
	ll t;	//cin >> t;
	t = 1;

	while (t--) {

		just_solved_it();
		cout << endl;
	}

	return 0;
}