<?php
$n = trim(fgets(STDIN));
$m = trim(fgets(STDIN));
$ms = explode( " ", trim(fgets(STDIN)));
$i = 0;
    sort($ms);
    foreach( $ms as $key => $val){
       if( $n < 0 ){
            break;
       }else{
            $n -= $val;           
            $i++;
       }
    }
    echo $i;