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

int main(){
    int n; 
    scanf("%d",&n);
    int lolx = 0;
    int loly = 0;
    int sumx = 0;
    int sumy = 0;
    for(int a0 = 0; a0 < n; a0++){
        int x; 
        int y; 
        scanf("%d %d",&x,&y);
        if (a0 == 0)
            {
            lolx = x;
            loly = y;
        }
        if (lolx == x)
            {
            sumx++;
        }
        if (loly == y)
            {
            sumy++;
        }
    }
    if (sumx==n||sumy==n)
        {
        printf("YES");
    }
    else
        {
        printf("NO");
    }
    return 0;
}