<?php

$num = trim(fgets(STDIN));
$array = array();
for($i=0;$i<$num;$i++){
    array_push($array, trim(fgets(STDIN)));
}
$aCnt = max(array_count_values($array));
$safeNum = ceil($num / 2);
if($num > 1 && $aCnt <= $safeNum){
    printf("YES");
}else {
    printf("NO");
}