#include<bits/stdc++.h>
using namespace std;
#define D(x)        cout<<#x " = "<<(x)<<endl
#define un(x)       x.erase(unique(x.begin(),x.end()), x.end())
#define sf(n)       scanf("%d", &n)
#define sff(a,b)    scanf("%d %d", &a, &b)
#define sfff(a,b,c) scanf("%d %d %d", &a, &b, &c)
#define pb          push_back
#define mp          make_pair
#define xx          first
#define yy          second
#define hp          (LL) 999983
#define MAX         10
typedef long long int LL;
typedef pair<int,int> pii;

//3_point_orientation
LL triArea2(pii a, pii b, pii c) // includes sign
{
    LL ret = 0;
    ret += (LL) a.xx*b.yy + (LL) b.xx*c.yy + (LL) c.xx*a.yy - (LL) a.xx*c.yy - (LL) c.xx*b.yy - (LL) b.xx*a.yy;
    return ret;
}

pii pnt[MAX+5];
set<int> x, y;

int main()
{
    //freopen("c:\\Users\\User\\Desktop\\in.txt", "r", stdin);
    //freopen("c:\\Users\\User\\Desktop\\out.txt", "w", stdout);

    int i, j, k, n;

    sf(n);
    for(i = 1;  i <= n; i++) sff(pnt[i].xx, pnt[i].yy);

    for(i = 1; i <= n; i++)
    {
        x.insert(pnt[i].xx);
        y.insert(pnt[i].yy);
    }


    if(min(x.size(), y.size()) == 1) puts("YES");
    else puts("NO");

    return 0;
}