#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;
    int line_x, line_y;
    bool is_line_x = true, is_line_y = true;
    scanf("%d",&n);
    for(int a0 = 0; a0 < n; a0++){
        int x; 
        int y; 
        scanf("%d %d",&x,&y);
        if (a0 == 0) {
            line_x = x;
            line_y = y;
            continue;
        }
        if (line_x != x) {
            is_line_x = false;
        }
        if (line_y != y) {
            is_line_y = false;
        }
    }
    
    if (is_line_y || is_line_x)
        printf("YES\n");
    else
        printf("NO\n");

        
    return 0;
}