#include<stdio.h>

int main(){
    int i , n ,x[10],y[10] , first_x ,  first_y , flag ;
    while(scanf("%d",&n)==1){
        i = 0 ;
       while(i<n){
            scanf("%d%d",&x[i],&y[i]);
            i++;
        }
        first_x = x[0] ;
        first_y = y[0] ;
        flag = 0 ;
        for(i=1;i<n;i++){
            if(first_x==x[i]){
                flag = 1 ;
            }
            else{
                    flag = 0 ;
                    break;
            }

        }
        if(flag==1)
            printf("YES\n");
        else{
            for(i=1;i<n;i++){
                if(first_y==y[i]){
                    flag = 1 ;
                }
                else{
                        flag = 0 ;
                        break;
                }

            }
            if(flag==1)
                printf("YES\n");
            else
                printf("NO\n");
        }
    }

    return 0 ;
}