<?php

fscanf(STDIN , "%s", $line_1);
fscanf(STDIN , "%s", $line_2);

$line1 = str_split($line_1);
$line2 = str_split($line_2);

$line_all = array_merge($line1, $line2);

$count = array_count_values($line_all);

asort($count);

$ok = true;

foreach($count as $key => $value){
    if($value == 1 or $value %2 == 1){
        $ok = false;
        break;
    }
}

if($ok === true){
    echo "YES";
}else{
    echo "NO";
}