#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_i;
    int  n_n;
    int  n_x;
    int  n_y;
    int  n_x1;
    int  n_y1;
    bool b_latch_x = false;
    bool b_latch_y = false;
    
    scanf("%d", &n_n);
    
    for(n_i = 0; n_i < n_n; ++n_i) {
        scanf("%d %d", &n_x, &n_y);
        
        if(1 == n_i) {
            if(n_x1 == n_x)
                b_latch_x = true;
            
            if(n_y1 == n_y)
                b_latch_y = true;
        } else if(n_i > 1) {
            if(n_x1 != n_x)
                b_latch_x = false;
            
            if(n_y1 != n_y)
                b_latch_y = false;
        }
        
        if(n_i && !b_latch_x && !b_latch_y)
            break;

        n_x1 = n_x;
        n_y1 = n_y;
    }
    
    if(b_latch_x || b_latch_y)
        printf("YES\n");
    else
        printf("NO\n");
    
    return 0;
}