int main() { char* n_endptr; char* n_str = readline(); int n = strtol(n_str, &n_endptr, 10);

int xfirst;
int yfirst;
int h = true;
int v = true;
if (n_endptr == n_str || *n_endptr != '\0') { exit(EXIT_FAILURE); }
struct point *point_xy = malloc(sizeof(struct point) * n);
for (int n_itr = 0; n_itr < n; n_itr++) 
{
    char** xy = split_string(readline());
    char* x_endptr;
    char* x_str = xy[0];
    int x = strtol(x_str, &x_endptr, 10);
    if (x_endptr == x_str || *x_endptr != '\0') { exit(EXIT_FAILURE); }
    char* y_endptr;
    char* y_str = xy[1];
    int y = strtol(y_str, &y_endptr, 10);
    if (y_endptr == y_str || *y_endptr != '\0') { exit(EXIT_FAILURE); } 

    point_xy[n_itr].x = x;
    point_xy[n_itr].y = y;
}
xfirst = point_xy[0].x;
yfirst = point_xy[0].y;
//  dprintf(2,"%d <----xfirst----- -----yfirst------>%d\n",xfirst,yfirst);
 for (int i = 0; i < n;i++)
 {
    //  dprintf(2,"%d <----xfirst----- -----yfirst------>%d\n",xfirst,yfirst);
    // dprintf(2,"%d <----xfirst----- -----points------>%d\n",xfirst,point_xy[i].x);
    if (point_xy[i].x != xfirst)
    {
        h = false;
        break;
    }
 }
 for (int j = 0; j < n;j++)
 {

    if (point_xy[j].y != yfirst)
    {
        v = false;
        break;
    }

 }
if (h || v)
    printf("YES");
else 
    printf("NO");
return 0;

}