#include <cstdio>
#include <iostream>
#include <queue>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <cstdlib>
#include <vector>
#include <set>
#include <stack>
#include <cctype>
#include <fstream>
#include <sstream>
#include <bitset>
#include <utility>
#include <map>
#include <list>

using namespace std;

#define loop(x,y,z) for(int x=y;x<=z;x++)
#define pi acos(-1.0)
#define sz(a) (int)(a).size()
#define NMAX 2147483647
#define LMAX 9223372036854775807LL
#define pb push_back
#define mp make_pair
#define ll long long
#define pf printf
#define mem(x,y) memset(x,y,sizeof(x))
#define rep(x,y) for(int x=1;x<=y;x++)
#define pii pair<int,int>
#define pll pair<ll,ll>
#define gi(k) scanf("%d",&k)
#define gl(k) scanf("%lld",&k)
#define PI acos(-1.0)
#define eps 1e-8
#define fi first
#define sc second
#define inf 1e13
#define endl "\n"
#define FO(i,n) for(int i = 0; i < n; i++)
#define debug(x) cout << #x << ": " << x << endl

const int INF = (int) 1e9;
const long long INF64 = (long long) 1e18;

#pragma comment (linker,"/STACK:16777216")
#pragma warning(disable:4786)

int Set(int N , int pos){return N = N | (1 << pos); }
int Reset(int N , int pos){return N = N & ~(1 << pos); }
bool check(int N, int pos){return (bool) (N & (1<<pos)); }
double dis(int x1, int y1, int x2, int y2) {return hypot(x1-x2, y1-y2);}
ll   GCD(ll a,ll b){ if(b == 0) return a; return GCD(b,a%b);}       //
ll   LCM(ll a,ll b){ return a*b/GCD(a,b);}

const int mx=1<<29;
int ans,sum,t,n,k,m,tag;
pii ar[111];

int dx[] = {0,1,-1,0,0};
int dy[] = {0,0,0,1,-1};

int main()
{
    //ios::sync_with_stdio(false);cin.tie(0);
    //freopen("00_input.txt", "r", stdin);freopen("00_output.txt", "w", stdout);
    
    gi(n);

    rep(i,n)
    {
        gi(ar[i].fi); gi(ar[i].sc);
    }

    tag = 0;

    rep(i,n-1)
    {
        if(ar[1].fi == ar[i+1].fi) continue;

        tag = 1; break;
    }

    if(!tag)
    {
        pf("YES\n"); return 0;
    }

    tag = 0;

    rep(i,n-1)
    {
        if(ar[1].sc == ar[i+1].sc) continue;

        tag = 1; break;
    }

    if(!tag)
    {
        pf("YES\n"); return 0;
    }

    pf("NO\n");

    return 0;   
}