<?php
 
try{
 
    $result = "";
 
    fscanf(STDIN, "%d %d", $a, $b);
 
    $now = true; // 현재 차례 패티의 차례 (false일 시 치즈의 차례)
 
    $count = 0;
 
    while(true){
        if($now){
            if(!$a) break;
            $a--; $count++;
        }else{
            if(!$b) break;
            $b--; $count++;
        }
        $now = !$now;
    }
 
    if($count % 2){
        $count--;
    }
 
    $result = $count;
 
    echo $result;
 
}catch(Exception $e){
    echo $e->getMessage();
}
 
 
 

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NCA1

4 5