#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 row = 0, col = 0;
    bool rowSame = true, colSame = true;
    for(int a0 = 0; a0 < n && (rowSame || colSame); a0++){
        int x; 
        int y; 
        scanf("%d %d",&x,&y);
        if (a0 == 0) {
            row = x;
            col = y;
        } else {
            rowSame &= row == x;
            colSame &= col == y;
        }
    }
    if (rowSame || colSame) {
        printf("YES\n");
    } else printf("NO\n");
    
    return 0;
}