#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>


int check(const int *a, const int s) {
    int ref = a[0];
    for (int i = 1; i < s; ++i) {
        if (a[i] != ref) return 0;
    }
    
    return 1;
}

int main(){
    int n; 
    scanf("%d",&n);
    
    int xs[n];
    int ys[n];
    for(int a0 = 0; a0 < n; a0++){
        int x; 
        int y; 
        scanf("%d %d",&x,&y);
        xs[a0] = x;
        ys[a0] = y;
    }
    
    if (check(xs, n) || check(ys, n)) fprintf(stdout, "YES\n");
    else fprintf(stdout, "NO\n");
    
    return 0;
}