/****************************************

@_@
Cat Got Bored *_*
#_#
*****************************************/

#include <bits/stdc++.h>


#define loop(i,s,e) for(int i = s;i<=e;i++) //including end point

#define pb(a) push_back(a)

#define sqr(x) ((x)*(x))

#define CIN ios_base::sync_with_stdio(0); cin.tie(0);

#define ll long long

#define ull unsigned long long

#define SZ(a) int(a.size())

#define read() freopen("input.txt", "r", stdin)

#define write() freopen("output.txt", "w", stdout)


#define ms(a,b) memset(a, b, sizeof(a))

#define all(v) v.begin(), v.end()

#define PI acos(-1.0)

#define pf printf

#define sfi(a) scanf("%d",&a);

#define sfii(a,b) scanf("%d %d",&a,&b);

#define sfl(a) scanf("%lld",&a);

#define sfll(a,b) scanf("%lld %lld",&a,&b);

#define sful(a) scanf("%llu",&a);

#define sfulul(a,b) scanf("%llu %llu",&a,&b);

#define sful2(a,b) scanf("%llu %llu",&a,&b); // A little different

#define sfc(a) scanf("%c",&a);

#define sfs(a) scanf("%s",a);


#define mp make_pair

#define paii pair<int, int>

#define padd pair<dd, dd>

#define pall pair<ll, ll>

#define fs first

#define sc second

#define CASE(t) printf("Case %d: ",++t) // t initialized 0

#define cCASE(t) cout<<"Case "<<++t<<": ";

#define INF 1000000000   //10e9

#define EPS 1e-9

#define flc fflush(stdout); //For interactive programs , flush while using pf (that's why __c )

using namespace std;
int x[1000];
int y[1000];
int main()
{
    int N;
    sfi(N);
    loop(i,1,N)
    {
        sfii(x[i],y[i]);
    }
    int ans1  = 1 , ans2 = 1;
     loop(i,2,N)
    {
        if(x[i-1]!=x[i])
            ans1 = 0;
        if(y[i-1]!=y[i])
            ans2 = 0;
    }

    if(ans1 == 1 || ans2 ==1)
        cout<<"YES"<<endl;
    else
    cout<<"NO"<<endl;


    return 0;
}